Category: Fish

People of the Salmon: Haida Tribe Defends Salmon with Science in Alaska

The Haida community on Prince of Wales Island, Alaska, have long considered themselves “people of the salmon.” They rely on the fish for their food and culture. Now community members are being trained to become scientists. Their assessments could help get their streams protected under Alaska state law.

Full Article

Weird Nature: Shrew-Eating Trout!

The story of rodent-eating trout at The Nature Conservancy’s Silver Creek Preserve has been one of our blog’s biggest hits. But those Silver Creek trout look like dainty eaters compared to this one. Meet the shrew-eating trout documented by researchers at Alaska’s Togiak National Wildlife Refuge. And how did this many small mammals end up in a trout’s stomach?

Full Article

Penobscot River Dam Removal: Lessons for a World Demanding Energy

Dam removal on Maine’s Penobscot River means a brighter future for Atlantic salmon and other migratory fish. But an even greater value of the Penobscot may in fact lie in its meaning for countries that are just now beginning to plan and build dams.

Full Article

Fishing for Clues: Investigating Fisher Behavior in a Tropical Purse-Seine Fishery

How do fishers decide when, where and how to fish? How does this influence fishery management and protection? Tim Davies presents his research on how tropical purse seine fishers make their decisions, and the implications for conservation. This is the second essay in a three-part series featuring blogs by the student prize winners at the University of Queensland’s Student Conference on Conservation Science,

Full Article

Dead Wood & Migrating Salmon: Restoring a Southeast Alaska Stream

A neat and tidy stream may look bucolic, even scenic. But for salmon it’s a dead end. On Prince of Wales Island in Southeast Alaska, land managers once removed dead wood from streams to “clean” them. That action was based on assumption, not science. Salmon need dead wood. They need diversity. Now a restoration effort is putting the logs back into the stream, creating “fish condos” for salmon.

Full Article

Quick Study: A California-Style Approach to Sustainable Fisheries

Quick Study is just what it says — a rapid-fire look at a new conservation science study that might turn some heads.

The Question(s): For decades, ocean bottom trawling has been the predominate method for catching groundfish (like flounder, halibut and sole) along the U.S. West Coast. But dragging weighted nets across the seafloor is destructive to bottom habitats and can result in large amounts of bycatch (netting of other species, including some that are ecologically valuable). Could a market-based approach to buy out trawl permits, combined with a collaborative effort to identify and protect ecologically sensitive areas, help protect species and a fishing industry?

Full Article

Bristol Bay Blog, Part 3: A Future for Salmon?

Editor’s Note: This is the final installment in a three-part blog series on the Conservancy’s recent research at Bristol Bay, conducted to provide a risk assessment of the proposed Pebble Mine.

Can one of the world’s largest mines be built in the headwaters of the world’s largest salmon fishery without disrupting the ecosystem?

That’s a question that generates a lot of controversy for the Bristol Bay watershed.

“There is a lot of vilification and name calling, but we wanted to go past that and get the data,” says Dave Albert, director of conservation science for The Nature Conservancy in Alaska.

The Nature Conservancy in Alaska commissioned an ecological risk assessment to improve understanding of baseline conditions near the Pebble deposit as well as potential risks such a mine could pose to salmon.

The baseline studies showed that juvenile salmon are ubiquitous in headwaters near the Pebble deposit, including documentation of more than 100 miles of previously unknown salmon streams. It also documented the purity of the water. “This is about the cleanest water in the world,” says Albert. “It’s not distilled water, but it’s pretty darn close.”

The ecological risk assessment used a cutting-edge stream modeling system to investigate potential effects of large-scale mining facilities including open pit mines, a tailings impoundment and waste rock dumps on stream headwaters.

The model results indicate potential for significant negative effects, including up to 60 percent reduction in stream flows near the pit and contamination from waste rock that could exceed Alaska water quality standards. The giant waste rock piles generated by mining would require active pumping and water treatment; if these systems failed, the levels of copper in the river could rapidly exceed lethal levels for salmon.

According to the researchers: “Our study shows that while some of the flow and water quality changes brought about by mining could be ameliorated by ambitious mitigation measures and water management plans, severe water quality effects could result from even a brief failure of these systems.”

The proposed mine dwarfs all other mines in Alaska combined; because the ore exists in low concentrations preliminary designs developed by the mining company show the mine covering twenty square miles with a massive tailings impoundment. From preliminary information released by the company, this tailings pond would require perpetual mediation in an area known for active earthquakes.

“We haven’t seen a detailed mine and water management plan, but it would be difficult to envision a project of this scale that does not require active management, basically forever, to avoid contamination,” says Albert.

Full Article

Bristol Bay Blog, Part 2: The Salmon Portfolio

Editor’s Note: This is the second in a three-part blog on the Conservancy’s recent research at Bristol Bay, conducted to provide a risk assessment of the proposed Pebble Mine. Yesterday’s blog covered background and research methods.

This is a land shaped by salmon—in ways large and small, apparent and obscure. Fly over Bristol Bay, and the impact of salmon is everywhere, in literally every living thing.

“Salmon built much of the Alaska we see today,” says Dave Albert, director of conservation science for The Nature Conservancy in Alaska. “At historic levels of abundance, salmon are a fundamental driver of any ecological system they inhabit. They’re in the bears and the eagles and the trees and the berries and the people.”

Unlike at most salmon-producing regions of the world, at Bristol Bay scientists can still study a full and functioning salmon ecosystem. The sockeye salmon populations in this region are the most productive in the world. These stocks have contributed an estimated 51 percent of all global sockeye production since 1970. And there are four other salmon species found here as well.

The life history of salmon is well documented. Salmon are hatched in freshwater streams. After growing large enough to make the lengthy journey, they swim to the sea. In the ocean, they grow large while eating smaller fish.

After two to four years, they return to the stream of their birth, lay eggs that will become a new generation of salmon, and die. Their bodies become food for bears and a whole host of other scavengers. Bits of salmon flesh are gobbled by rainbow trout, char and other fish. They nourish algae in the water that provides food for aquatic insects that in turn become food for the next generation of salmon offspring.

“Salmon are in essence a nutrient-delivery system,” says Albert. “They bring nutrients from the rich marine environment to the nutrient-poor rivers and lakes, generation after generation.”

Full Article

Bristol Bay Blog, Part 1: Understanding Remote, Wild Waters

No fishing hyperbole: We caught something every other cast. At least.

Huge king salmon spawned in the river, but these were not the fish we were seeking. It was the fish following the king salmon. A host of species lined up downstream as the kings spawned, picking off eggs as they drifted past. We cast little beads that imitated the eggs and bam! Fish on!

Maybe it was a grayling or a large rainbow trout or a char. It didn’t matter: it was the greatest fishing of my life.

That was my first afternoon in the Bristol Bay watershed. The ensuing days there seemed like a parade of wonders: volcanic mountaintops, bears roaming lakeshores, hooking silver salmon in the rain, more rainbow trout and grayling and char.

Here’s the thing: We weren’t even there for the main event—the largest sockeye salmon runs on earth that taken together produce more sockeye salmon than the rest of the world. Combined.

Just last evening, we baked one of our Bristol Bay silver salmon fillets, and the memories came rushing back—memories of one of my finest adventures in a life filled with the pursuit of outdoor experiences around the globe.

And so I understand well the passion, the emotion, people feel for this place, especially when a gigantic mine is proposed right in the midst of it.

The Bristol Bay watershed is located in southwestern Alaska, a mind-bogglingly wild expanse of rivers and streams that covers 58,000 square miles. It has always been best known for its salmon population and the subsistence, commercial and recreational fisheries it supports.

Lately, though, Bristol Bay has received even broader attention, with the proposed mine most commonly known as the Pebble Mine. As it happens, Bristol Bay also sits atop the largest copper and gold deposit on earth. By most estimates, Pebble Mine would be the largest copper mine in North America and one of the largest in the world.

Full Article

Fish and Chimps

Chimpanzees don’t eat fish. They don’t even swim. But at Lake Tanganyika in western Tanzania, scientists have found that to save chimps, they must look underwater.

That’s because here, everything—people, fish, water, forest, and chimps—is interconnected. Attempting to conserve the apes without accounting for the health of the fishery that provides food and income for local people would doom these efforts.

Today, fish supplies are dwindling, villages are growing fast and chimps are getting squeezed into smaller and smaller forests.

Full Article

Results: Great News for Shad

Standing on the bow of the boat, Steve Herrington exuded the excited energy of a kid reeling in his first fish. Or perhaps a more scientific version of the Crocodile Hunter, bubbling with intensity. Net in hand, he scooped up shad — a migratory fish species — quickly examining them before passing them off to fellow researchers.

As covered in yesterday’s blog, last year I spent a day with Steve on Florida’s Apalachicola River looking at Alabama shad, a fish that researchers hoped would benefit by a practice known as conservation locking—basically allowing fish to pass through dams by using the same lock system that enables ships to pass.

Herrington was then director of freshwater programs for The Nature Conservancy’s Florida program (he now holds the same position with Missouri). At the time, conservation locking on the Apalachicola seemed to hold great promise for shad, a migratory species. He estimated that conservation locking could result in a returning population of 60,000 to 75,000 shad, indicating a steady increase.

Fast forward a year later. Herrington is on the phone, and that same infectious enthusiasm is literally bubbling over. “Great news!” he exclaims.

And indeed, his research has yielded surprising results. Those initial estimates of 60,000 shad? Way low. Estimates now showed a 122,000 fish increase, with as many as 280,000 total shad now in the system.

“We can now confidently say that conservation locking works, and we’re seeing a substantial bump in the population,” Herrington says. “I don’t know that there are any other data out there that so convincingly demonstrates such effectiveness.”

Full Article

A Lock Holds the Key to Restoring Migratory Fish

Author’s Note: This blog originally ran a year ago, following time afield with shad researchers on Florida’s Apalachicola River. Recently, the researchers released new information with some exciting new results on Alabama shad restoration. This blog provides the background information on the project. Check back tomorrow for a look at the results of this project, which is making a big difference in migratory fish conservation.

Take PVC pipe. Attach to a home water pump. Add water.

It’s a simple recipe, but one that might be enough to help move millions of the migratory fish species known as Alabama shad over dams, so they can spawn in rivers throughout the southeastern United States. For millions of dollars less than conventional methods. With potentially big gains for sport fisheries in those rivers.

“It’s low cost, low risk and low tech,” says Steve Herrington, director of freshwater conservation for The Nature Conservancy in Florida. “You can buy any of the basic equipment at Home Depot. And we have the science to back it up.”

Full Article

Research Results: If You Restore It, Will Pike Come?

It’s well known that some migratory fish species, like salmon, are able to trace their way back to the stream where they were born. However, conservationists have no idea if this is the case for hundreds of other fish species.

Do pike return to spawn in the streams where they were born, a la salmon?

Not necessarily, at least in the Green Bay watershed. If there’s suitable habitat, pike will find it and spawn. That’s the central finding of research conducted by the University of Wisconsin’s Pete McIntyre and Dan Oele.

This result may sound like a let-down, but in reality it’s a relief for conservationists in the Green Bay area. The Nature Conservancy and other conservation groups are focused on restoring streams for pike and other fish, but the best methods to accomplish that goal remain uncertain. If pike returned to their natal streams to spawn, they may never find a restored stream even if it contained suitable habitat.

That’s not the case, which is good news for conservation efforts.

Full Article

Notes from Silver Creek: Computer Modeling for Stream Conservation

What effects will land use changes have on a stream and its wildlife? How do conservation managers know what will happen in a stream when a restoration project takes place? Will it really lower water temperatures? Will fish thrive?

Surely conservationists can’t see into the future? 

Actually, stream managers now use sophisticated computer modeling to predict the outcomes of their activities. These models allow them to see how planting native shrubs, for instance, will alter stream flows and water temperatures.

In 2010, The Nature Conservancy was contacted by Maria Loinaz, a PhD candidate  at the Technical University of Denmark and the University of Idaho.  She was interested in developing a hydrologic model of the Silver Creek watershed using software called MIKE SHE/Ecolab.

This software is changing the way stream managers engage in restoration. It incorporates data on both groundwater and surface water, including stream flow, precipitation, vegetation and soils to accurately predict the effects of a new activity on a stream.

Maria proposed using the MIKE SHE program to model the groundwater and surface water systems and use the EcoLab program to build a water temperature model. Together these would allow her to model what happens to stream temperatures when riparian buffers were planted or stream flows increased.  Maria also wanted to incorporate fish data to see whether she could model where, based on the hydrology and temperature, fish would thrive in the system.

Full Article

Discovery: New Cave Fish Species Sees “Light of Day”

Deep inside a remote cave in northern Vietnam, Craig Leisher aimed his headlamp at the water. Several small, strange-looking fish flashed by. He readied his butterfly net and quickly tried to scoop one up but missed. He tried again.

Leisher eventually caught four species of fish. Further analysis revealed that two species were already known to science, one was a new species and one was a mystery.

The new species, Schistura mobbsi, has no eyes, no pigmentation and a limited ability to sense motion. It is a type of loach — a river-dwelling genus that includes both subterranean and above-ground species.

Leisher and ichthyologist Maurice Kottelat recently published the discovery in Ichthyological Explorations of Freshwaters … 10 years after the fact.

Why did it take 10 years for Schistura mobbsi to make its public appearance in the scientific literature?

Let’s re-wind.

Full Article


This Week on Cool Green Science: Change & The Eastern U.S. Forest

Too many deer. Logging one tree to save another. Beavers versus old growth. Welcome to forest conservation in the Anthropocene. Beginning Monday, July 21, join us for a provocative 5-part series exploring the full complexity facing forest conservation in the eastern United States.

Featured Content

Osprey Cam: Watch Our Wild Neighbors
Watch the ospreys live 24/7 as they nest and raise their young -- and learn more about these fascinating birds from our scientist.

What is Cool Green Science?

noun 1. Blog where Nature Conservancy scientists, science writers and external experts discuss and debate how conservation can meet the challenges of a 9 billion + planet.

2. Blog with astonishing photos, videos and dispatches of Nature Conservancy science in the field.

3. Home of Weird Nature, The Cooler, Quick Study, Traveling Naturalist and other amazing features.

Cool Green Science is managed by Matt Miller, the Conservancy's deputy director for science communications, and edited by Bob Lalasz, its director of science communications. Email us your feedback.

Innovative Science

Investing in Seagrass
Marine scientists and fishers alike know that grass beds are valuable as nursery habitat. A new Conservancy-funded study puts a number to it.

Drones Aid Bird Conservation
How can California conservationists accurately count thousands of cranes? Enter a new tool in bird monitoring: the drone.

Creating a Climate-Smart Agriculture
Can farmers globally both adapt to and mitigate the impacts of climate change? A new paper answers with a definitive yes. But it won't be easy.

Latest Tweets from @nature_brains

Categories