The Torrent needs you!
Have an environmental or fly fishing related issue you want to share? Issues with your favorite river? Proposed development in a sensitive area? Volunteering opportunity for habitat rehabilitation? Tell us about it! This is not a witch hunt or a place to whine - but somewhere to deliver objective information. Even better if you have a way to help. There is a lot of doom and gloom out there - but don't forget the silver lining.
Use the contact page or email thetorrentflyfishing@outlook.com
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Saving the remarkable Una River
The Una river, forming part of the border between Croatia and Bosnia & Herzegovina, is in trouble. The picturesque tributary of the Sava River running through the Balkans area of Europe is home to 17 threatened species and is one of the final strongholds of the Huchen, or Danube Salmon (Hucho hucho). The river is sourced from one of the world’s deepest karstic springs and is recognised as a Natura 2000 protected area by the European Environment Agency.
Despite these protections, a private company is going ahead with construction of a dam to produce hydroelectricity near the headwaters of the Una as this piece is being written. The project has received worldwide criticism as well as protests by citizens and officials from the three countries whose lands border the Una.
The project is undergoing assessment by officials to ensure it has all the necessary permits required for the construction following speculation that the company had not conducted a comprehensive environmental assessment. Protesters are continuing to put pressure on authorities to stop the project and are campaigning to get Croatia’s Prime Minister to intervene.
If you need any convincing that this river needs protecting, please take the time to watch this video, first shared on this website in November 2023, and PLEASE sign the petition, and/or donate below.
What can you do?
Sign the petition
Change.org: Protect the Una River and Surrounding Ecosystem
Donate
Balkanrivers.net: Save the Blue Heart of Europe – A campaign for the protection of Balkan Rivers.
British Columbia to ban open net-pen salmon farms by 2029.
In June of this year, the Department of Fisheries and Oceans Canada (DFO) announced that open net-pen salmon farming in the coastal waters of British Columbia will be banned by June 30, 2029.
While this is a major win for wild Pacific salmon, that have suffered from disease and sea lice infestation from these farms, that are operating within wild salmon migration routes, the decision has been met with scepticism from some.
And you really can’t blame the sceptics – it wasn’t all that long ago (2021) when DFO stated they would put an end to open net-pen farms and transition to closed containment fish farms by 2025. Now, wild salmon have to survive another four years past the initial deadline while populations continue to experience long term declines from myriad other factors in the death-by-a-thousand-cuts maelstrom we humans have created for them.
To put the shoe on the other foot, the salmon farm industry in B.C. employs 5000 workers and the B.C. Salmon Farmers Association claims the industry is worth $1.2 billion to the Canadian economy. To the workers, I sympathise, and this is where the government needs to step in to provide sustainable alternatives, like fully contained farms which don’t pose a threat to the wild fish. The government says they will help industry transition to these goals. They also said that in 2021.
And while there is no question that open net-pen Atlantic salmon farms contribute significantly to the Canadian economy, it comes at the enormous cost of wild salmon that are providing immeasurable ecosystem services in their roles as keystone species.
“Keystone species means that if a species is removed, things start to collapse. It means it’s the key to the lock that opens the door to the whole ecosystem …” says Pacific salmon biologist Dr. Alexandra Morton.
Putting a dollar value on wild salmon and the services they provide is difficult, but there is no doubt it is a monumentally larger figure than what the farms contribute. To the economy alone, continuing BC open net-pen farms is cutting off your nose to save your face. To the British Columbian coastal ecosystem, it’s suicide.
Washington State, just south of the B.C. border banned open net-pen farming in public waters in 2022. The state commissioner of public lands at the time, Hilary Franz stating; “As we’ve seen too clearly here in Washington, there is no way to safely farm finfish in open sea net pens without jeopardizing our struggling native salmon. Today, I’m announcing an end to the practice. We, as a state, are going to do better by our salmon, by our fishermen, and by our tribes. Commercial finfish farming is detrimental to salmon, orcas and marine habitat. I’m proud to stand with the rest of the west coast today by saying our waters are far too important to risk for fish farming profits.” (Commissioner Franz’s full order is available here).
The decision to ban open-net pen salmon farms in Washington follows the August 2017 collapse of a net-pen which released hundreds of thousands of Atlantic salmon into Puget Sound.
It seems it is now time for Canada’s DFO to follow Washington’s lead and put their money where their mouth is, and champion the needs of wild salmon over the destructive industry practices they have allowed to continue in coastal waters for far too long.
Open net-pen Atlantic salmon farm. (Image: seattletimes.com)
Hooked Tarpon predation by Hammerheads an increasing problem in Bahia Honda - a popular Florida Keys fishing destination
Sharks have become an increasing concern for both recreational anglers and the fish species they target in recent years throughout fisheries worldwide. Flats and inshore reef fisheries in tropical and sub-tropical areas seem to be the hotspots, but the issue can occur in any saltwater or estuarine fishery. So what is the issue? Simply put – hooked, or recently released fish are being attacked and eaten by sharks.
This subject is highly controversial. Anglers may be upset that authorities are not doing anything about the huge shark population, conservationists are being told that shark numbers worldwide are plummeting, and they need protecting – but who is right?
It’s great that people on both sides of the argument are passionate about the subject – it means they care. But, like many things, it’s easy to get caught up in our own personal experience without taking the chance to step back and look at the big picture in a more objective way.
One thing most of us can agree on is that humans are voracious when it comes to screwing up the natural world, and our global fisheries have felt the heavy brunt of this. Sharks are still being killed in huge numbers worldwide, but the effects of this might not be seen on the flats and reefs of our inshore fisheries. Why? Maybe because the species targeted by commercial fisherman typically don’t inhabit inshore fisheries – maybe the species suffering crippling declines are mainly oceanic. Perhaps the bulk of shark fishing occurs in international waters, or another part of the world, and we don’t see the effects at our local fishing spots – it's something for us all to think about.
Why then are we seeing increases in predation of hooked fish by sharks in our inshore fisheries? It may be that sharks have changed their habits to capitalise on an easy meal. The natural world is like that. (Why do seagulls hang around picnic areas and fish and chip shops?). Another reason could be that the food chain has been screwed up so much (see trophic cascades) that sharks have no choice but to change their inshore feeding habits to survive. Again, something to think about.
A recent study, published 2024, has investigated the predation of hooked Tarpon by Great Hammerhead sharks in the waters surrounding the island of Bahia Honda in the Florida Keys. Tarpon come inshore during spring months around the keys and form a world-renowned flats fishery worth $272 million annually (together with bonefish and permit) in Florida alone. While depredation by sharks (primarily hammerheads and bull sharks) is reportedly increasing in the keys, the habit is hardly new with reports of sharks killing hooked fish in Florida waters as early as 1911. Nevertheless, the problem in Bahia Honda has become so bad that guides have raised concerns about the future of the catch-and-release fishery there.
The study of 394 hooked Tarpon found fatalities from sharks during the fight and immediately post-release was 15.3% for all Tarpon that were hooked and fought for 5 minutes or longer. This compares to a 2011 study in Boca Grande Pass and Tampa Bay that discovered 13% of all Tarpon hooked died after release, and 64% of those fatalities were caused by sharks. Interestingly, the 2024 study noted that depredation risk was highest during the first 5-12 minutes of the fight and during an outgoing current. They found the Hammerheads habits changed during outgoing currents where they concentrated in areas overlapping with Tarpon, which likely led to the increased shark/angler interactions.
The researchers concluded that Bahia Honda has great ecological significance to both Great Hammerhead sharks and Tarpon. They stress that anglers using best practices – including efforts to reduce fight times and ending a fight early (busting them off) when sharks are present will be critical to ensure the future of this unique fishery.
Bahia Honda with study area shown (red circle). Inset: Florida Keys showing position of Bahia Honda.
Great Lakes steelhead benefit from Saugeen River dam removal.
Rainbow trout have been in the Great Lakes system since their introduction in 1874 and have settled nicely into three distinct life histories there: lake residents, river residents and adfluvial (migrating to rivers). There is a lot of conjecture whether the migrating trout should be called lake-run rainbows, or steelhead – but for the purposes of this piece, I’m going to refer to them as steelhead (see more here). Great Lakes steelhead are legendary (perhaps not quite as legendary as their wild, west coast counterparts) and form an important part of the multi-billion dollar recreational fishery of the Great Lakes system. Incredibly, very little scientific study has focused on their migratory habits and the effects that dams have on migration when forming potential barriers on Great Lakes rivers and tributaries.
A 2024 study conducted on the Saugeen River which drains to Lake Huron, has helped to remedy this, and understand the effects of dams and dam removal on the migratory habits of these unique fish. The Saugeen River has many dams and weirs on both the main stem of the river and some of its tributaries. Some of the dams have been fitted with fishways to help passage of migrating fish, with varying degrees of success. One dam, identified as a potential barrier to fish migration, the Truax Dam, on the Saugeen’s main stem, was removed in 2019 and researchers have focused on how the dam removal has affected the habits of migrating steelhead. Fish were able to find passage past the Truax dam, but the question is, how much of an obstacle was the dam, and how much did it delay the migration run?
The researchers tagged 368 fish between 2018 and 2022 and found that the delay in moving upstream at the dam site decreased from an average of 8.2 down to 0.3 hours, for spring run fish, 44.4 down to 0.7 hours for Fall run fish – reducing further to 0.5 hours for Fall fish the following season. What’s more is that more fish (not surprisingly) were able to pass beyond the dam site. Before the dam removal 61.8% of spring and 17.6% of fall steelhead made it beyond the dam site, increasing to 86.7% for spring fish and 84.8% of fall runs after dam removal. This means more steelhead are moving upstream to tributary spawning grounds than had previously been possible prior to dam removal.
Migratory fish blocked by dams face delays in migration, increased predation risk, potential thermal stress and exhaustion of energy reserves. Dam removal reduces or eliminates these adverse effects, or, in the words of the researchers, “From a fisheries perspective, dam removal restores riverine habitat, returns flow and thermal regimes to undammed conditions, and eliminates barriers that either delay or block upstream fish passage.”
Truax dam on the Saugeen river being removed 2019. (Image:brockton.ca)
Water temperature at time of catch-and-release critical for post-catch survival of Atlantic salmon.
Water temperature related fishing closures are becoming more commonplace in salmonid fisheries as anglers, environmentalists and government bodies become increasingly concerned about the welfare of cold-water fish in an ever-warming climate. Movements like Keep Fish Wet are spreading the word about best handling practices to give released fish the best chance of post-catch survival, but how does water temperature come into it?
As water warms, it holds less dissolved oxygen, which makes it harder for fish to ‘breathe’. Added to that, metabolic rate in ectotherms (cold blooded animals) increases as the temperature in their environment increases, requiring more oxygen to feed that metabolism. It’s a vicious circle. It makes sense then, that trout and salmon would become stressed as water temperature increases, and want to avoid vigorous activity as a means of self-preservation. When we catch cold water fish that we intend to release, we need to be mindful of water temperature when we catch them to avoid drastically reducing their chances of survival after release. But what is that magic threshold?
A team of researchers in eastern Canada has found that 20°C is the absolute maximum water temperature that Atlantic salmon (Salmo salar) can be caught and released without seriously reducing their chance of post-release survival. The 2024 study, showed that 22% of all salmon, caught and released using single, barbless hooks died after release when the water temps at time of capture were 20°C or above. This compares to 8% salmon mortality for fish caught on single barbless hooks when water temps were below 20°C. The study found that water temperature fluctuations before and after capture had little effect on survivability – what was critical was the temp at the time of capture.
The researchers have commended rules restricting salmonid fishing during afternoons when water temperatures rise (often known as ‘Hoot-Owl’ restrictions) and the use of best practices when handling cold-water species. As the climate continues to change, and weather extremes become more common, increasing use of hoot-owl restrictions in cold-water fisheries will help to reduce mortality of the world’s, already struggling, trout and salmon species.
This helpful TU chart applies not only to trout, but many other salmonids too. The 68°F 'STOP FISHING' marker is 20°C - the absolute upper threshold for Atlantic salmon for catch-and-release before post release mortalities increase dramatically.
May Vid Features: LAKES - Scottish Pike, Canadian Brook & Rainbow trout & U.S. Alpine Cutthroat Trout
Alpine Rocky Mountain Cutts
Credit: Redington
Scottish Pike - Loch Style
Credit: CJsReelAdventures
Stunning BC Brookies
Credit: jensenflyfishing
BC Chironomid action - Rainbows
Credit: BradKnowlesPembertonFishFinder
April 2024 News
California hatchery steelhead losing biocomplexity
California’s Central Valley steelhead population is now dominated by hatchery-origin fish, since billions of smolts have been continually released from four hatcheries within the catchment since the late 1940’s. A 2024 research article has found that while hatchery fish accounted for 3-18% of steelhead returns in the 1950’s, this percentage had increased to 63-92% of returns by 2000. This hatchery fish dominance has drastically reduced the complexity and distinction of the various strains of the species unique to each part of the catchment – instead creating more bland and genetically similar fish across the board. In the words of the researchers: “One issue that exacerbates hatchery dominance is that program goals often focus on achieving a total number of fish released rather than maximizing biocomplexity and resiliency.” They concluded, “Management actions that promote biocomplexity should be approached within a scientific and monitoring framework to assess changes in stock resilience over time”
Sea trout suffering from hatcheries, industry
A comprehensive study of 1251 Norwegian watercourses has found that sea trout (anadromous brown trout – Salmo trutta) populations are classified as good or very good in less than 25% of the watercourses and in a poor to very poor state in 40%. 29 watercourses had lost their sea trout populations altogether. Among the human induced factors contributing to the decline, sea lice from salmon farms was found to be most impactful, affecting 83% of watercourses, 60% of river areas and total sea trout abundance. Aquaculture, agriculture, and hydropower were more closely linked to sea trout populations than human population density, even though exploitation was found to be moderate to high in 14% of watercourses studied. Sea trout are a popular target species for fly anglers and provide important ecosystem services throughout the rivers they inhabit.
More river pollution from old Canadian coal mines
On the heels of last month’s BC mining disaster legacy (The Flow – Mar 24) comes another example of continued pollution stemming from old mining activity. A research article published last month proves contaminants including lead and selenium are still entering Rocky Mountain rivers decades after the closure of mountaintop coal mines. The long abandoned Grassy Mountain and Tent Mountain coal mines continue to leach contaminants into the Crowsnest River watershed 40 years after mining activity ceased. Researchers found selenium levels in water downstream of the mine sites exceeded provincial and federal guidelines. Selenium bioaccumulates in fish, affecting reproductive capacity – a major concern for the area’s rainbow, cutthroat and brook trout and native Rocky Mountain whitefish. Nitrate levels, sourced from the mines, were also found to exceed water quality guidelines for the protection of aquatic life.
Plastics causing DNA damage in bass
Concerning news from a recent study on Australian bass (Percalates novemaculeata, or, Macquaria novemaculeata – depending on which taxonomist you talk to) showing micro and nano plastics (MNPs) from food items are embedding into tissues at a cellular level causing damage to DNA. Bass were fed brine shrimp (artemia) containing NPs (from 50nm – 1µm in size) for 5 days to determine what effect it had on the fish. The results showed that the smaller plastics accumulated in brain and muscle tissues of the bass at higher concentrations, while the larger NPs were primarily found in gills and intestines. The NPs were found to activate harmful superoxides in tissues and damage DNA. The study shows new perspectives on the toxic impacts of NPs on fish and the transfer of plastics throughout the food chain.
Rapidly declining water quality in NZ rivers, lakes
Pollution of New Zealand’s renowned freshwater lakes and rivers has increased to the point of ‘crisis’ claims a 2024 research article. The “rapid intensification” of agriculture - particularly dairy farming - throughout much of the country is a major factor contributing to the loss of water quality. Forestry, horticulture and the “chronic underfunding of storm and wastewater systems” in intensifying urban developments is also being blamed, however fingers are being strongly pointed toward the agriculture sector where 85% of waterways in pasture catchments now exceed Australasian nitrate guideline thresholds. 44% of lakes, nationally, are now eutrophic – up from 10% (pre-development). While mild eutrophication can have positive effects on aquatic plant growth which can boost food chains, excessive eutrophication can cause algal blooms, low dissolved oxygen levels and fish kills, potentially threatening NZ’s iconic trout fisheries. More here.
Grayling habitat varies with age and size
Arctic grayling (Thymallus arcticus) have been found to prefer different habitat at different elevations depending on their life stage. A recent study in Canada’s Yukon and Northwest Territories has discovered young-of-year grayling prefer lower elevation streams (< 1000m) and water temperatures above 8°C, while adults preferred higher elevations (1200m+) and water temps averaging 7°C. As fly anglers – this gives us a clue where to find bigger grayling at high latitudes, but importantly helps us understand upper and lower thresholds within river habitat variables for each life stage to help our “ability to support decisions by land and resource managers that make ecological sense for the species”. The research raises concerns of habitat sustainability in a changing climate as populations will need to adapt, move or suffer losses as trends continue.
April Vid Features: Anadromous fish on the fly!
Steelhead - Northern BC
Credit: The New Flyfisher
Coastal Cutthroat and Coho salmon - Puget Sound, WA
Credit: Catch Magazine
Atlantic salmon - Ireland
Credit: Gardiner Mitchell Irish Angling
Sea trout - UK
Credit: Flyfishing Londoner
March 2024 News
Size of Murray cod determine water temp and oxygen tolerances
Iconic Australian Murray cod (Maccullochella peelii) are suffering from increasingly frequent fish kills as drought conditions and human based water use increase, often leaving chains of stagnant ‘refugia’ pools in normally flowing rivers for fish to survive in. Such conditions can push the fish beyond their upper thermal limits and below their lower oxygen limits causing mass die-offs. A recent study has found that both oxygen and thermal tolerance of these fish will change with the fish’s size. Larger fish were found to be less tolerant of higher water temperatures than smaller (fry) fish, while smaller fish could handle lower dissolved oxygen levels than the larger fish. The study indicates both very young/small fish and very large/old fish are at greatest risk as the combined impacts of a warming/drying climate and increased water extraction affect native fish habitat.
Largemouth bass having little effect on invasive silver carp
Non-native and highly invasive silver carp (Hypophthalmichthys molitrix) are taking over the Mississippi River basin. A recent study in the Illinois River has looked at the relationship between the “large-gaped” (hence the name) largemouth bass (Micropterus nigricans) and silver carp to determine if enhancing the bass fishery throughout the basin is likely to substantially reduce carp populations through “top-down” predation. Of the 389 largemouth bass sampled, researchers found that 18% of the piscivorous bass contained evidence of silver carp and, (perhaps not surprisingly) a significant relationship between the length of bass and the length of the carp consumed was observed. The study concluded that enhancement of the largemouth bass fishery was unlikely to have any significant impact on silver carp populations.
Pink salmon spreading across Arctic and Atlantic Europe
This news follows the Icelandic article from The Torrent’s October 2023 feed. Unlike many anadromous salmonids throughout their native ranges, which are experiencing population declines due to human induced stressors, pink salmon (Oncorhynchus gorbuscha) continue to thrive and expand their population and range throughout the Arctic and Atlantic basins following deliberate release in northern Russia in the 1950’s. Runs of invasive pinks reached a high in 2021 where the species outnumbered native Atlantic salmon in Norwegian rivers. Scientists are struggling to keep up with the species expansion, predicting they will “(adversely) impact the behaviour of adult Atlantic salmon, sea-run brown trout and Arctic char during river entry, upstream migration, and holding before spawning …” The 2023 study deems the issue “to be a high-priority research area in both marine and freshwater sciences”.
Canada's DFO delays closure of open net pen salmon farms
It’s no secret that open-net pen salmon farms are having catastrophic effects on wild salmon populations (both Atlantic and Pacific) where wild and domestic fish interact. While the wheels of change have been turning slowly on Canada’s west coast, NGO’s such as Canada’s livingoceans.org are holding the Department of Fisheries and Oceans (DFO) accountable to make good on their promise of removing all salmon farms from BC waters by 2025. Land based salmon farms, such as Vancouver Island’s Kuterra facility have already proven sustainable without the risk of pathogens and pollutions harming wild salmon. Despite this, DFO are inexplicably in consultations with industry to renew open-net pen salmon farm licences for terms of 2-6 years when they expire in June of this year. More here.
Mine spill still polluting a decade after tailings dam disaster
Almost 10 years since the world’s second largest mine tailings breach in history, residual copper-rich sediment from the Mount Polley Mine disaster continues to pollute salmon and trout habitat downstream of the spill site. In August 2014, 25 million m3 of polluted water and mine tailings were released into Hazeltine Creek and subsequently Quesnel Lake and Quesnel River. A study of >400 sediment samples from Quesnel River gathered since the spill has found copper concentrations continuing to spike during winter to levels “which exceeds Canadian sediment quality guidelines for the protection of aquatic organisms”. Copper can be lethal to aquatic species as it accumulates within cells due to a lack of regulatory systems to purge excess concentrations. The annual winter spike has been attributed to autumnal turnover of Quesnel Lake’s water disrupting previously settled toxic sediment.
Declining lake levels threaten Lahontan cutthroat forage species
The highly prized and unique Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) fishery of Nevada’s Pyramid lake may be threatened if lake levels continue to decline. The largest sub-species of cutthroat trout depend on the Tui chub (Siphateles bicolor) as their primary food source to grow to such epic sizes. Tui chub depend on rocky nearshore habitat to spawn – habitat which has decreased as lake levels declined 98 feet from 1891 to 1967 due to water extraction. A recent master’s thesis has indicated that further lowering of lake surface level will significantly impact chub spawning habitat with adverse knock-on effects for the lake’s trout population. The results will have important implications for Pyramid Lake water demands to ensure survival of healthy populations of both species.
March Vid Features: All about that BASS
Smallmouth - Canada
Credit: So Fly
Largemouth - USA
Credit: Huge Fly Fisherman
Australian bass - Australia
Credit: Peachy Fly Fishing
Peacock bass - Brazil
Credit: Catch Magazine
February 2024 News
'Snow drought' affecting Alaskan fisheries and ecology
Lower than normal winter precipitation leading to lower snow accumulation, combined with higher temperatures is causing precipitation to fall as rain rather than snow in salmon-bearing Alaska. Climate modelling predicts reducing snowfall along Bering Sea and Pacific coast Alaska will affect salmon bearing rivers. “Changes in climate affect snowpack and thus streamflow volume, water availability, and seasonal timing of runoff. Historically SW Alaska watersheds have been considered snow dominant, but by 2100 at least some streams will have fully shifted to rain dominant regimes” claims a recent report. Winter flooding, when salmon eggs are gravel bound, is predicted to increase, possibly leading to scouring, while spring flooding is likely to decrease, indicating potential for seasonal timing shifts in salmon migration.
Mixed results for fish habitat with Tibetan dam construction
Researchers on Tibet’s Lancang River have studied the effects on spawning sites due to dam construction of two native fish species (Schizothorax spp.). The study found that main channel habitat will be damaged by dam construction, yet tributary spawning habitat upstream of the dam will be improved due to the influx of backed up water into the tribs. This predicament favours one species of fish and detriments the other. Mitigation by use of spur dykes to alter hydrology, and sediment (spawning substrate) replenishment, however, is predicted to improve main channel spawning habitat to minimise impacts on both species. Researchers suggest the restoration model could be applied to other rivers with both natural habitat and manmade infrastructure.
'New' trout species observed spawning in Morocco
A newly discovered trout species endemic to Africa? Who’d have thought?! The Dades trout (Salmo multipunctatus) has recently been observed spawning in its only known habitat high in the Atlas Mountains of Morocco. 12km of the Dades River headwaters and 10km of its tributary, the M’Goun are the only places on Earth where these trout are known to exist. Researchers discovered spawning behaviour not previously seen in other salmonids such as probing of the anal fin into substrate, by females, to test suitability of spawning gravel and pair bonding prior to spawning notably different from that observed in other species. These unique trout have only been recorded at elevations greater than 2145 metres. Link to study here.
Effects of habitat restoration on salmon/steelhead resilience to climate change
Using the Habitat and Restoration Planning (HARP) model, researchers on the USA’s Chehalis River conducted a study to determine how various habitat restoration techniques would affect Coho salmon, Spring-run and Fall-run Chinook salmon, and Steelhead under current climate conditions. The most effective measures for increasing spawner numbers across all species were floodplain reconnection, wood augmentation and fine sediment reduction within rivers. Increasing beaver pond area benefitted Coho the greatest, while increasing shade proved beneficial to all species, with Coho and spring-run Chinook displaying the greatest uplift in spawner numbers. With climate change effects added, all species were negatively affected (without restoration techniques) with spring-run chinook taking the hardest hit from late century flood flow increase and water temperature increases.
Organic pollutants affect iconic UK chalk streams
The clear, alkaline waters filtering through the UK’s chalk aquifers produce some of the most unique spring creeks on Earth and are among the most iconic and historically significant rivers to the sport of fly fishing. A recent comprehensive study has detected a chemical cocktail of man-made pollutants within two of these – the Itchen and Test Rivers. 81 plant protection products (including herbicides, fungicides and pesticides), 35 industrial chemicals and 115 pharmaceutical products were detected. The study found agriculture was the main source of plant protection chemicals, while sewage outflows were responsible for pharmaceuticals. Researchers stress the importance of further study as the effects of these chemicals on the river’s ecological community is still largely unknown.
Temperature mitigation measures best chance to save Mediterranean brown trout
Mediterranean river temperatures are predicted to increase up to 2.2-2.9°C by 2100, with 80% of these rivers in High Risk (HR), or Very High Risk (VHR) of losing brown trout populations by this time. Also alarmingly, 92% of the rivers in the area are in the HR, or VHR of affecting the macroinvertebrate community. Risk of habitat loss and ecosystem damage is also very high. Dissolved oxygen level decreases of 0.5 to 0.75mg/l are predicted, with a recent report claiming restoration of riparian vegetation to reduce water temperature, protection of groundwater and cold-water discharges from reservoirs the best mitigation measures to save brown trout populations and the greater ecological communities of the riverine Mediterranean region.
February Vid Features: SPRING CREEKS
New Zealand
Credit: Trout Hunting NZ
United Kingdom
Credit: Aardvark McLeod Fly Fishing
Montana
Credit: Montana Angler Fly Fishing
Patagonia
Credit: Jensenflyfishing
January 2024 News
Bull trout changing range with changing climate
Bull trout (Salvelius confluentus) occupy a very narrow ‘thermal niche’ compared to many other salmonids, preferring colder water than many other species with little variance in water temperature. A recent study has shown that the species distribution is limited in the north (Yukon, NW Territories, CAN) by colder water temperatures and streams freezing to the bottom, and in the south (Oregon and Idaho, USA), by warmer water temperatures and greater fluctuation in temperature throughout the year. As the global climate warms, range contraction in the south (away from lowland streams to higher elevations), and expansion in the north (extending range as more rivers become habitable) is likely, or maintaining current range will depend on the species ability to rapidly acclimatise to changing thermal conditions.
Caribbean flats fishery will look very different within decades
The impacts of climate change are expected to have significant negative impacts on flats fisheries throughout the Caribbean by 2050. A recent study has predicted a “very high magnitude of change” can be expected on inshore flats fisheries due to rapid warming and the increasing incidence, and severity, of damaging storms. The study group including 17 fishing guides, resource managers, and science and policy experts working in fisheries systems in Belize and/or The Bahamas suggest bonefish are likely to display “high vulnerability” to changes, while permit and tarpon may be less vulnerable based on observations of resilience to disturbance and habitat flexibility. To enhance climate resilience in recreational flats fisheries, strategies at individual, community, national, and international levels were a primary focus of the study.
Species success dependent on angling technique: management implications
An interesting Japanese study has highlighted how different angling techniques affect catchability of different coldwater species. In a lake fishery containing endemic Miyabe char (Salvelinus malma miyabei), introduced rainbow trout (Oncorhynchus mykiss) and introduced Masu salmon (O. masou), researchers studied the catches of 398 anglers using either fly (107) or lure (246) techniques, or both (44 [other, 1%]). Results showed that the majority of the lure anglers catch (73%) was the native Miyabe char, with 20% of their catch consisting of rainbow trout. Fly anglers caught a higher percentage of rainbows (47%) and a lower percentage of Miyabe (48%) in comparison to lure anglers, while both techniques accounted for similar catches of Masu salmon (lure 7%, fly 5%). The research highlights the need to consider angling techniques when implementing management and conservation protocols for fisheries.
Expected brown trout range shift in Himalayas as climate warms
Introduced brown trout have successfully inhabited the rivers of India’s Himalayan region since the early 1800’s. An extensive study factoring in 83 environmental variables has recently been undertaken to determine expected distribution changes resulting from climate change. Modelling showed an extensive network of suitable habitat opening up for brown trout as the climate warms, however much of the habitat encroaches on river sections currently occupied by native species such as snowtrout. It is not clearly understood how brown trout will affect native fish populations into the future, however researchers stress the need to not only prioritise areas for the reintroduction of brown trout into the future but consider the protection of “pristine areas” predicted to fall within the species future range.
Tigerfish populations suffer from artisanal overfishing
Tigerfish (Hydrocynus vittatus) populations may be in jeopardy, in Zimbabwe’s Lake Kariba due to overexploitation from artisanal and recreational fishing. The region is a popular location for targeting tigerfish on fly, however a 2023 study reports populations may be under threat from both legal and illegal gillnet fishing. Researchers highlight the need for regulatory authorities to step in and engage fishers in helping to reverse the long-term trends of tigerfish population declines. Overfishing is driven primarily by “poverty and a lack of livelihood alternatives”, meaning addressing the issue will not be easy, however implementing a “multi-stakeholder and holistic approach” is regarded as the best strategy to recover and conserve the fishery.
Salmon farm escapees hybridizing with wild Atlantics
A Norwegian study has found that domesticated Atlantic salmon escaping from fish farms are at high risk of breeding with wild salmon in nearby rivers. Trapping salmon entering the Etne River over a four-year period, researchers discovered over 50% of recently escaped domestic fish and 96% of early escapees were mature (capable of spawning) upon entering the river. Each year, tens of thousands of domesticated Norwegian salmon are reported as having escaped from fish farms, posing great risks to wild populations through introgression (hybridization of wild and domesticated fish) and increasing risk of disease transmission from domesticated to wild fish. The researchers have highlighted the need for continued vigilance by salmon farmers and management authorities to avoid risks of salmon escaping from open net pens.
January Mix: Flats fishing - freshwater and salt.
Time to get you feet wet and rod bent!
Bonefish in The Bahamas
Credit: The Fly Project
Montana Mud Marlin
Credit: The Fly Project
Northern Australian Permit
The Magic of the Seychelles
Credit: In the loop magazine
December Mix: Winter fishing begins in the north, while southern summer options open up.
Cutties and couloirs: skiing and winter trout fishing
Credit: Redington
NZ: Summer trout fishing in pristine rivers
Credit: Catch Magazine
Colorado: Winter tailwater fishing
Credit: Redstone Fly Fishing
South Africa: Drakensburg trout fishing
Credit: Fish On Line
December 2023 News
GT's show favourable response to catch and release on fly.
A 2022 study conducted in the Seychelles indicates giant trevally are resilient to catch and release fly fishing with air exposures of up to 30 seconds. Researchers studied 30 fly caught GT’s and a control group of 12 caught by handline, monitoring them for 10 minutes post release after air exposures of 0, 15 or 30 seconds. Locomotor activity increased after five minutes of observation, post release, across all groups with just one handline caught fish, mortally wounded due to being gill hooked. The study suggests Alphonse Island GT’s show great survivability from responsible fly fishing techniques, yet researchers stress that further research in different habitats upon different populations is needed. Check out the amazing Seychelles fly fishing here.
Taimen conservation progressing across Mongolia/Eurasia
Did you know there are five species of Taimen spread across the Eurasian continent from Poland to Japan? The largest and most well known is the Siberian Taimen, commonly sought after within the rivers of Mongolia. All species are apex predators and along with other “freshwater megafish” have, sadly, among the highest population declines of any vertebrate group on Earth. However, a 2023 research article states recent, and ongoing, research into the genera Hucho and Parahucho (the taimens) has led to protected areas for these fish in Russia, Mongolia and Japan. Significantly, conservation minded angling programs are proving to be effective for protecting populations, helping community run taimen stewardship incentives and aiding education and anti-poaching enforcement to help reduce the taimens’ vulnerability for population declines.
Politics muddy the trout fishing waters of South Africa
Salmonids are not native to South Africa yet were introduced here in the late 1800’s, providing sport for fly anglers since. Trout don’t breed successfully here – the fishery being dependent on hatchery releases. Attempts by post-apartheid governments to control trout are “… seen by many white (property) owners as a state attempt to undermine private property”, states a 2022 study. The paper further implies that trout are seen as emblems of colonialism, and if governments are able to control hatcheries through legislative acts, they can “eliminate owners ability to maintain private stocks”, threatening the country’s trout fishery. To view what trout fishing in South Africa is like, see this month’s videos in The Flow, or click here.
Rubber preservative killing Coho in storm runoff
A chemical used to preserve rubber, used in tyre (tire) manufacturing is causing mortalities in pacific salmon, with Coho especially sensitive. The chemical, 6PPD transforms into 6PPD-quinone when exposed to ozone in the atmosphere, and it is this lethal form causing concerns for salmon populations. The chemical enters rivers through stormwater runoff from roads and streets and is lethal to most salmonids, with Coho displaying the greatest sensitivity. The Rocky Mountain Outlook reports first nations tribes are petitioning governments to ban the use of the chemical, though tyre manufacturers are yet to find an effective replacement. A 2023 study reports that coho exposed to the chemical display “… loss of equilibrium and buoyancy, and eventual death.” Sadly, exposed fish do not recover if transferred into clean water.
NZ native fish behaviour studied in trout presence
Are introduced trout impacting stocks of native galaxiids?. And what are galaxiids? - The southern hemisphere’s answer to salmonids in the north – occupying similar niches in freshwater habitats. Galaxiids, though, are typically smaller than salmonids, are scaleless and have a single dorsal fin located where the adipose fin of a salmonid would be, and of little sportfishing value. A 2022 Masters thesis has found NZ galaxiids show little behavioural changes in the presence of predatory brown trout, potentially exposing them to greater predation risk. An estimated 10% of trout and galaxiid habitat overlap, and the study found that benthic structure (cobbles or sand) was more indicative of galaxiid behaviour that was the presence of trout.
High survivability of catch and release Danish sea trout
Encouraging news from a Danish study which suggests anadromous brown trout, or sea trout (Salmo trutta) are highly resilient to catch-and release methods via different recreational fishing techniques. Researchers monitored trout for 26-29 days after being released noting bleeding being common (post-release), yet no mortalities occurred.
Fish were caught via lure (treble hook #4), bait (single hook #1/0) and fly (single hook #12) with only the trebles being responsible for unhealed wounds (6% of fish) by the end of the experiment. The study concluded that further research is needed to corroborate results under more natural field conditions and any sub-lethal impacts of catch and release fishing should also be investigated.
Special Feature: Remembering Eric Olsen 1935 - 2023
Eric Olsen was a Port Moody, BC, Canada, fly fisherman who loved to chase pacific salmon, steelhead and coastal cutthrout trout in BC. He is best known for his tireless work propogating Chum and Coho salmon at Noons Creek Hatchery and his dedication to salmon habitat restoration and conservation. He was instrumental in repopulating the waters of British Columbia with millions of salmon, and inspired hundreds of volunteers with his infectious love of salmon ecology and conservation. Often known as a 'fish whisperer', it is eerily fitting that the first salmon of the year repopulated the creek he worked so hard for, just in time for his memorial service. He will be deeply missed.
Search for 'Noons Creek Hatchery' on Facebook to see more of Eric's service, or learn more about the community run hatchery here.
Image: PMES
Video Credit: Sandra Niven
November Mix: The problem with dams, The life of Joe Humphreys and, can mining and fly fishing coexist?.
Serbia: Huchen and the fight to save the Una River
Credit: Brothers On The Fly
The extraordinary life of fly fishing icon Joe Humphreys
Credit: Gravitas Ventures
Dams: Are they doing more harm than good?
Credit: Patagonia
Contradictions: A miners love of fly fishing
Credit: Redingtongear
November 2023 News
Native Huchen endangered in Balkan rivers
Europe's largest freshwater salmonid the Huchen, or Danube salmon (Hucho hucho) was historically found throughout all but the alpine reaches of the Danube River basin. From the early 1800's however, overharvesting and habitat degradation have led to the species vanishing from much of its former range. The few free flowing rivers left within its range support most of the remaining population, but impending dam construction threatens the huchen and its pristine habitat further. To help save wild Huchen and wild Balkan rivers, join the Patagonia campaign or show support at balkanrivers.net. To learn more about Slovenian Huchen populations, click here.
Himalayan Snowtrout display climate change resilience
Studies in Bhutan have shown Himalayan Snowtrout (Schizothorax spp.), generally considered a high-altitude species, can tolerate much lower altitude rivers than previously thought. Though in the same family as Common carp, Snowtrout display morphological similarities to salmonids and prefer habitat and water temperature ranges similar to brook trout. The species ability to tolerate lower altitude rivers and a wider array of habitats than many 'true' trouts, however, indicates an ability to adapt to climate change - important as Himalayan glaciers, feeding the rivers, continue to retreat. In many of Bhutan's rivers, Snowtrout coexist with introduced brown trout. To fish for these species in Bhutan, see divine fly fishing or learn more about Snowtrout here.
The Brumby War: Saving Australia's alpine wilderness
Australia's alpine areas cover a mere 0.3% of the continent and host dozens of endemic plant and animal species. It is also home to some great rainbow, brown and brook trout fishing. Feral horses (known locally as Brumbies) have been allowed to roam free through the region's National Parks due to their significant cultural value, despite the damage they cause to the creeks and alpine meadows with their hoofed feet. Whether horses should remain in alpine parks has been hotly debated for years, however the NSW government has recently declared it will reduce numbers of horses by aerial culling due to horses placing the entire alpine ecosystem under threat. See what Australian alpine fly fishing is all about here.
Pharmaceuticals accumulating in Florida's bonefish
A 2023 study in Florida has discovered bonefish are accumulating pharmaceuticals in their tissues, raising concerns as to what behavioural effects these drugs will have on the species. Researchers tested samples of bonefish for 102 common drugs, detecting 53 present among the sample population with an average of 7.1 pharmaceuticals present per bonefish. The maximum number of different drugs found within an individual bonefish was 17. Human prescription drugs enter waterways, typically, via effluent outflow, and while you may think drug concentrations may be highest closet to urban areas, the study found the highest incidence of drug accumulation was found at the studies most remote sampling location. The study suggests changes to wastewater treatment are needed to prevent pharmaceuticals from entering the marine environment.
Selenium continues to affect Elk River water quality, BC.
Arguably the World's greatest Westslope Cutthroat trout and Bull trout waters - British Columbia's Elk River watershed - continues to suffer from increasing Selenium (Se) levels originating from the area's mountaintop coal mines. Selenium is a natural element, harmless at low levels, however regular testing since the 1980's has shown Se concentration within the Elk has steadily increased beyond safe levels for aquatic species since around 1990. Such high levels can affect the reproductive capabilities of fish, leading to birth deformities and mortalities, reducing population fitness and size. To learn more, donate, or get involved, visit the Elk River Alliance.
Diadromous fish migrations changing with climate
A recent study in Ireland has shown timing of three diadromous fish species (Atlantic salmon, brown trout and European eel) migrations have changed since 1970. Most dramatic was Atlantic salmon, whose returning adult spawning migrations have advanced 1 - 2 months since 1970. This finding coincides with a reduction in adult body size and reduced numbers of salmon returning over the study period, indicating signifificant challenges are being faced by these fish while at sea. Salmon smolts are making downstream migrations one week earlier than in 1970 also. The researchers stress that while the study population showed significant migratory changes in timing, it's difficult to generalise as each local population throughout the range will be subject to different conditions and variables, however ongoing research will be critical to save the species from possible local extinctions.
Habitat Restoration: Four examples of how this practice benefits fish, wildlife - and your fishing experience.
UK Chalkstream Restoration
Credit: Chalkstream Fly
Canada Salmon Pathways
Credit: Pacific Salmon Foundation
US Culvert Removal
Credit: SPSSEG
Bahamas Mangrove Replanting
Credit: Bonefish & Tarpon Trust
October 2023 News
Pink salmon populations establishing in Iceland
During May 2022, pink salmon (Oncorhynchus gorbuscha) smolts, were discovered in three Icelandic rivers - the first evidence the species are spawning successfully there, and well outside of their native north Pacific basin. A 2023 study claims the fish are believed to be descendants of successful stockings in Russia's White Sea tributaries during the 1950's-1970's.
Pink Salmon sightings are increasing throughout Europe and the UK, raising concerns the invasive species may impact populations of native salmonids such as Atlantic salmon, brown trout and Arctic char.
Push for Australia to develop national habitat restoration plan.
With climate change and questionable land use and water management practices adversely affecting the precious water sources in the world's driest continent, Ozfish Unlimited are among the many environmental advocates pushing for a national plan to implement habitat restoration practices within Australia's rivers and wetlands. Ozfish are a not-for-profit organisation specialising in habitat conservation and restoration. Help out Australian waterways and fish by signing up for membership, or volunteering at a local chapter.
Pesticides instigating DNA changes in Chilean mayflies
A recent study in Chile's Limari River revealed 100% of sampled mayflies showed effects from agricultural pesticides. This includes DNA methylation that, in mammals, is known to affect central nervous system (CNS) functioning, leading scientists to question agricultural practices in the region. The Limari and surrounding Chilean rivers hold genetically diverse populations of rainbow trout (Oncorhynchus mykiss), extensive native fauna and a growing central Chilean human population.
Introduced rainbow trout outcompeting Slovenia's native marble trout
A study in an Idrijca river tributary has shown rainbow trout (Oncorhynchus mykiss) bullying Slovenia's native marble trout (Salmo marmoratus) with aggresive behaviour and pushing the natives away from preferred habitat. The rainbows tended to gather in small groups while the marbles found habitat individually, taking twice as long as the rainbows to settle into their surroundings. Scientists fear the rainbows are adversely affecting marble trout populations and are calling for end to stocking of non-native salmonids in areas where marble trout are known to occupy.
Calls for stakeholder engagement in Cuban bonefish management
Researchers are engaging Cuban fishers, government and third parties to formulate a management plan to protect Cuba's bonefish (Albula vulpes) populations. Utilising successful strategies implented elsewhere, the push for better management aims to focus on six key areas including the implementation of restricted fishing during times, and in areas, where the species are known to congregate for spawning. The Cuban bonefish fishery is an integral part of the Atlantic and Caribbean recreational flats fisheries worth more than US$750 million. Read more here.
NorCal's riparian zones affected by increased occurence of droughts.
Rivers draining San Francisco's bay area have shown changes in riparian vegetation resulting, from climate change. The study, looked at 21 years of data, determining riparian areas suffered rapidly from drought, but recovered quickly during wetter conditions. Vegetation close to river sources at higher elevations showed increasing vegetation density while lowland sections showed some loss. The study showed river sources fed, primarily, by snowmelt faired better than rainfed rivers and that lowland sections suffered from a lack of agricultural irrigation runoff and water engineering. Increases in atmospheric CO2 may be contributing to overall net increases in riparian vegetation throughout the study area due to CO2 fertilisation effect.
Fish Farming - how does it affect wild anadromous fish?
Artifishal
Salmon Confidential
Credit: John L. Beath
Credit: Patagonia
Fly Tying: One Minute Ant
Credit: The Torrent
Fishin': West Credit River
Credit: So Fly
September 2023 News
EPA clean water update & river conservation: reasons for hope
The U.S. federal government has revised its definition of 'Waters of the United States' rule. See how Hatch magazine views how the revision will affect American waterways, or register for a webinar outlining the changes on September 13th or September 20th
What can be done to save the resources we love when it all seems too overwhelming? In episode 500 of the Wet Fly Swing podcast, you will find reasons to be encouraged that good science is making changes for the better - and every little thing you do does make a difference.
Didymo Update: Check, clean, dry.
It's no secret that invasive Didymo (Didymosphenia geminata) has run riot throughout NZ's South Island. See how you can curb the spread of waterborne invasives - and this applies to ANY fishery throughout the world. See the 2012 study showing evidence of dish detergent being most effective decontaminant for waders/clothing - better than bleach!
Australian Trout Foundation - Volunteers needed
The ATF promotes and protects Australia's unique trout fisheries. Habitat restoration projects are at the heart of what they do, so help our trout by registering for a volunteering project, or sign up for membership to keep Australia's trout fishing world class.
Raw sewage pumped into UK streams 825 times per day
UK water companies have been releasing raw sewage into the streams and rivers of England causing ecological damage to trout and salmon habitat. Find out why this happens, and check out the great activism helping to keep the polluting corporations accountable in this episode of the Fly Culture Podcast.
Find out which waters are threatened by pollutants in the UK State of the water environment indicator.
Upper Skagit (BC) protected and threats to the West Credit River (ON)
OK, so old 'news' maybe, but worth celebrating - the donut hole in BC's Upper Skagit river catchment has been protected from mineral prospecting and logging, thus protecting the unique native trout habitat on the Canadian side, and water quality downstream into the U.S.
The range of Brook trout in the Credit River watershed has diminished alarmingly over the past 200 years. The West Credit River is one of the last strongholds for brookies in the system. Listen to this heartfelt podcast and watch the video to find out how important this river is, what it means to anglers and conservationists, what issues the West Credit faces and what can be done about it.
Drought cripples Italy's Po River
Many regions of Italy have been declared a state of emergency as drought takes its toll, adversley affecting water flow in the Po - once described as 'The king of rivers'. However many Italian trout rivers continue to thrive - if you have ever dreamed of fishing Italy, Alpsflyfish is a great place to whet your appetite.