Layout Image
Page 1 of 3123
Print This Post Print This Post
Conferences and Events, Fish Report, Mekong Basin

Some fish passage workshop attendeesScientific research can inform the best designs and strategies to help fish move past migration barriers, such as dams, weirs, and road crossings. That was the take-home message of the Lao National Workshop on Fish Passage that FISHBIO recently attended in Vientiane, Lao People’s Democratic Republic. Experts from Lao PDR, Australia, Brazil, France, and the United States shared experiences addressing fish passage in their respective countries. Speakers stressed that fish passageways in Lao PDR need to be designed specifically for the native species of the region, which may require different approaches than those that have worked elsewhere. A particular challenge to fish passage design in a region with as much biodiversity as the Mekong is accommodating the wide variation in sizes and swimming abilities of fish species that range from 3 cm to 3 m in length.

The conference focused primarily on floodplain barriers, which block fish from moving laterally off the main river into the tributaries and wetlands of the watershed. The first day of the workshop focused on helping fish traveling upstream, which may be breeding adults trying to migrate to their spawning grounds, or juveniles accessing nursery habitat. Researchers presented methods for prioritizing existing structures that need modification for fish passage — a necessary exercise, since they identified nearly 2,500 potential barriers in a single river catchment (Xe Chamopone). Such barriers can be roads, irrigation structures, or natural obstructions like logs. Scientists also described an experiment to test various fish passage designs at a floodplain regulator in the Pak Peung wetland of Central Lao PDR (Baumgartner 2012). Unlike salmon, which can leap over barriers 2 m high, Mekong fish in the 3-60 cm size range could generally clear a step that is 10 cm tall (4 in), the researchers found during laboratory studies. Based on these findings, they constructed a fishway with 43 sequential 10-cm steps, which stretched 150 m (492 ft) in length. Because fish passageways can’t be too steep, the taller a barrier is, the longer a fishway needs to be to clear it, and hence the more expensive it is to construct and maintain.

The second day of the conference focused on creating passage for downstream migrating fish, which can be either adults or juveniles travelling from floodplains to the mainstem river. Several researchers discussed the potentially hazardous hydraulic conditions fish may encounter when passing through structures, including pressure changes, shear between two shifting masses of water, and collision with hard surfaces. Researchers indicated that structures requiring water and fish to pass underneath a barrier (such as a sluice gate) proved more damaging to fish than those allowing fish to pass over the top of a structure (such as a fixed crest weir). Scientists also used a pressure chamber to demonstrate the barotrauma, or physical injury from changes in pressure, that fish experience when passing through turbines and weirs: as the pressure drops, the gasses inside a fish expand. Participants discussed plans to build fish swimming and testing facilities at the National University of Laos so more fish passage experiments can be conducted on a greater variety of local species. The workshop highlighted many successes in helping fish move across floodplain barriers, which are generally 6 m (20 ft.) or shorter. A number of additional factors will need to be considered when designing and evaluating fish passage at larger barriers.

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Print This Post Print This Post
Conferences and Events, Fish Report, Predation

pikeminow salmon predation

The role of predation in aquatic ecosystems can be a complex matter, and when it concerns Central Valley salmon and steelhead populations, a contentious one as well. Recently, the California Department of Fish and Wildlife (CDFW) held a two-day workshop in Davis, California, to obtain independent scientific input on the topic of predation from an expert panel. The primary purpose of the workshop, titled “State of the Science Workshop on Fish Predation on Central Valley Salmonids in the Bay-Delta Watershed” was for the panel to evaluate and summarize the current state of knowledge related to predation in the Central Valley. In addition, the panel was charged with developing a strategy for future research to reduce scientific uncertainty related to predation. In mid-September, the panel will issue a formal report that addresses the key questions of the workshop and future research strategies. Invited panel members were professors and researchers from the west coast, but came from as far away as Colorado State University and the University of Georgia. Their areas of expertise included fisheries, quantitative ecology, and hydrodynamic modeling. The CDFW Delta Science Program and NOAA’s National Marine Fisheries Service sponsored the meeting.

The workshop’s morning presentations acquainted both the panel and audience with the key biological, physical, and management aspects of the Bay-Delta system. Afternoon presentations covered more technical aspects of salmonid survival and predation, as well as population modeling efforts related to the Bay-Delta. The presentations were followed by a public comment and question period. A closed session was held during the morning of July 23, in which the panel drafted their initial responses to presentations and documents from the annotated bibliography. The panel presented their initial response during the afternoon session, again followed by a public comment and question period. The formal document that the panel issues in mid-September will address key questions of the workshop and future research strategies.

Key points of the panel’s initial response, while still preliminary, included that predator-prey relationships can be quite complex and rely on many different physical and biological conditions. They also noted that the underlying physical and biological environment of the Bay-Delta system has changed drastically in the past 50 years. Such changes include substantial shifts in community composition in fish, invertebrate, and plant communities in the watershed (Brown and Michniuk 2007), a decrease in overall turbidity, and extensive modification of channel configuration and shallow water habitats-all of which can affect predation dynamics.The panel also acknowledged that key information about predation rates over time and space are currently lacking. The panel concluded their remarks with initial recommendations for moving forward on the topic of predation in the Central Valley. First, they stressed that a clear management plan was needed to develop the type(s) of studies required for important management decisions regarding predation. Additionally, coordination and standardization of methods among fisheries researchers in the Central Valley is needed in order to address common research needs and objectives. As some of our work at FISHBIO focuses on predation (see What’s for dinner?, Last meal), we’ll be sure to keep an eye on this important topic.

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Print This Post Print This Post
Conferences and Events, Vaki Riverwatcher

nal Fish Passage conference

International Fish Passage conference

A big thank you to everyone who came out to visit FISHBIO and VAKI at the International Conference on Engineering & Ecohydrology for Fish Passage at Oregon State University last week. The conference was a great mix of international professionals interested in fish passage, and we had many stimulating discussions with the folks who stopped by our booth. We enjoyed the opportunity to meet engineers, biologists, managers, and public relations professionals from power companies like Bonneville Power, Idaho Power, Portland General Electric, Eugene Water & Electric, Alliant Energy, Duke Energy, and Pacificorp Energy. Many organizations in attendance displayed a wide array of products and services, and we were happy to include the VAKI Riverwatcher among them. The conference was a great opportunity for all to learn about fish passage engineering and restoration projects, both locally in regions like the Columbia Basin, and internationally in areas such as the Four Major Rivers Restoration Project in South Korea. We look forward to seeing what new ideas, collaborations, and projects develop from these interactions.  

 

Print This Post Print This Post
Conferences and Events, Vaki Riverwatcher

VAKI Riverwatcher

Technology can play an important role in monitoring and improving fish passage, and the VAKI Riverwatcher infrared scanner and fish counter is a prime example of such a tool. FISHBIO and VAKI will be showcasing the Riverwatcher at the International Conference on Engineering & Ecohydrology for Fish Passage at Oregon State University from June 25–28. If you missed our booth at the 2011 American Fisheries Society meeting in Seattle (see New frontiers), this is a chance to check out our fish carousel setup that demonstrates the Riverwatcher’s features and capabilities. Representatives from VAKI and FISHBIO will be on-hand to answer all manner of general and technical questions about the Riverwatcher and its applications.

The Riverwatcher can remotely monitor fish ladders, weirs, and fishways using infrared scanning technology and high-resolution cameras. Fish swimming between the Riverwatcher’s scanner plates break the infrared beams and create a silhouette image. A digital camera also records video or still images that can be used to identify the species and sex of each passing fish. The Riverwatcher counts and measures each fish, and records additional data such as passage date and time, flow speed, and water temperature. The Riverwatcher’s software program provides tools to analyze migration run size and timing, fish size classes, and associated environmental data.

FISHBIO has used Riverwatchers since 2003 to count and monitor adult salmon and other fish migrating upstream to spawn. We have had such great success with the fishing counting system that we teamed up with Iceland-based VAKI to sell and service the devices in North America. As the authorized service agent, FISHBIO installs Riverwatchers and provides on-site training, troubleshooting, and assistance with data analysis. We are looking forward to contributing to the upcoming conference in Corvalis, Oregon, which will highlight engineering, biology, management, and social issues surrounding fish passage and watershed connectivity projects. Please stop by our booth— we look forward to answering questions and exchanging ideas about fish passage solutions.

Print This Post Print This Post
Conferences and Events, Research, Salmon

Nigiri Project

Can fish and farms coexist in harmony? Scientists are currently trying to answer this question in the Yolo Bypass, a roughly 60,000-acre expanse of engineered seasonal floodplain habitat that sits upstream of the Sacramento-San Joaquin Delta in California’s Central Valley. This unique area was developed in the 1930s as a bypass for water from the Sacramento River to reduce the risk of flooding in the Sacramento area. It generally floods in the winter or spring when waters from the Sacramento River overflow the Fremont Weir. When the bypass drains in the late spring, the land is used for agriculture (most notably rice farming) and grazing. In recent years, biologists have begun to recognize the area’s importance as winter aquatic habitat for birds, fishes, and other wildlife (Sommer et al. 2001, Feyrer et al. 2006). As part of the Cal-Neva American Fisheries Society annual meeting, held last week in Davis, CA, the Department of Water Resources (DWR) and CalTrout hosted a tour of the Yolo Bypass for fellow fisheries biologists.

Nigiri Project on the Yolo Bypass

A highlight of the tour was stopping by Knaggs Ranch, located just north of the City of Woodland. CalTrout, DWR, and UC Davis have launched a study here investigating the potential to combine current agricultural practices  with floodplain habitat for fish and wildlife in the Yolo Bypass, dubbed “The Nigiri Project” (i.e., “fish on rice”), which has recently received a lot of press. Jacob Katz, from CalTrout and UC Davis, showed off the project site. Researchers have teamed up with farmers to investigate whether productive rice fields farmed during the summer can be managed in the off-season to provide winter habitat for juvenile Chinook salmon. The expansive habitat and somewhat regular flooding events in the Yolo Bypass offer a unique opportunity to test this rotation. They are just finishing the second year of the project, and rice grown on the experimental plots during the first year was harvested last fall (see top photo). Over the past two years this project has documented impressive growth of salmon that lived on the experimental habitat for six weeks: last year they recorded a five-fold weight gain, one of the highest growth rates for Chinook in the region. In 2013, fish were raised in various plots where the rice stubble left over from last year’s harvest was treated in different ways (e.g., stomped down, left as stubble, disked, or fallowed). The team is currently analyzing the results of the rice treatment portion of the study to see if fish benefit from particular rice stubble modifications. The AFS tour attendees observed the study fish before researchers released them into the river.  The fish are outfitted with acoustic tags so scientists can track their survival and migration to the ocean. Project participants are touting the collaboration as a rare win-win-win situation, with benefits for agriculture, wildlife, and flood protection. 

Print This Post Print This Post
Conferences and Events

FISHBIO team at AFS Cal-Neva Meeting

The California-Nevada Chapter of the American Fisheries Society (Cal-Neva AFS) recently held its 47th Annual Cal-Neva Conference in Davis, California. This year’s conference focused on the biodiversity of California and Nevada fishes, and provided scientists and managers the opportunity to present research findings and future study ideas. More than one hundred people attended, including several FISHBIO staff. This year’s plenary speakers included Dr. Peter Moyle (University of California, Davis), Steve Parmenter (USFW, Bishop Field Office), Dr. Sean Hayes (NOAA Fisheries, Davis), Dr. Walter Duffy (USGS, Humboldt State University, Arcata), and Dr. Zeb Hogan (University of Nevada, Reno).  Plenary speakers presented topics on the history, status, restoration, conservation, and management of California inland fishes, desert fishes (i.e. pupfish), coastal salmonids, and the world’s large-bodied fishes. 

Many fish populations are imperiled around the world, especially those in California and Nevada. Factors that negatively affect native fishes include habitat loss and degradation, climate change, predation, and interactions with non-native species. Dr. Moyle explained that extinction is a natural event; however, native California fish species are being listed as endangered or threated at an approximate rate of one species per year. Fish assemblages have shifted to be largely comprised of non-native fishes, which can often out-compete the native species due to their phenotypic plasticity (i.e. higher thermal tolerance range, larger body size, etc.), thereby reducing an ecosystem’s biodiversity. Dr. Walter Duffy stated that management must not only consider individual species, but should also incorporate the biodiversity of ecosystems, as well as the diversity within a species. This within-species diversity can include alternative life histories (i.e. Chinook salmon that spawn at different ages) and different races of salmon (i.e. fall run and spring run salmon).  Mr. Steve Parmenter discussed the importance of monitoring trends and effects of management activities, and shared efforts to restore populations of Owens pupfish in Death Valley. 

While the ultimate goal for many fish researchers is to prevent population declines and restore native fish populations, it is also important to consider natural events that cause mortality. As Dr. Sean Hayes put it, “salmon die,” and this is a completely natural event. Dr. Hayes discovered that the majority (85%) of the steelhead that return to spawn on Scott Creek in Santa Cruz, California, come from a small group of fish that spend the summer in an estuary instead of the ocean. Because “fatter” fish are present in high-growth habitats like the estuary, predators also seek out these habitats. Therefore, restoring habitat for salmon may also attract more predators, leading to higher fish mortality. Dr. Zeb Hogan finished the plenary session talking about the status of large Nevada fishes, pointing out that there are no Chinook salmon or Colorado pikeminnow and very few Lahontan cutthroat trout left in Nevada. Dr. Hogan, also renowned for his international research on large-bodied fishes, also discussed the status of large-bodied fishes around the world, such as the critically endangered Mekong giant catfish. The Mekong River watershed contains approximately 1000 different fish species and the majority of large-bodied fishes in the world. However, no single Mekong fish species has had its life history completely described, Dr. Hogan said. This year’s plenary speakers echoed the importance of fish biodiversity in California and Nevada waters, and around the world: managing to conserve biodiversity maximizes our efforts in not only recovering individual species, but also recovering ecosystems.

Print This Post Print This Post
Conferences and Events, Fish Report, Marine

Point Lobos State Marine Reserve

Underwater state parks. Ecological savings accounts. Noah’s Arks. These were all terms used to describe marine protected areas (MPAs) at the State of the California Central Coast Symposium recently held in Monterey, California. The symposium highlighted research conducted during the five years since California embarked on an ambitious mission in 2007: to establish a coordinated network of ocean areas off-limits to some or all fishing along the entire state coastline. At times controversial, the stakeholder-driven process came to a close last fall when the northernmost, final links in the MPA chain went into effect from Mendocino County to the Oregon border. The Monterey symposium focused on the first section of the MPA network established on the central coast from Pigeon Point to Point Conception in 2007. California’s statewide MPA network is the first of its kind in the country, and other states like Oregon are hoping to follow suit.

“The state of California is recognized as the leader in the design and implementation of MPAs,” said marine scientist Mark Carr from UC Santa Cruz who has played a large role in process. With people around the world watching California’s MPA experiment with interest, Carr said he and other scientists feel a serious responsibility to monitor and evaluate how these conservation and management tools perform. Some of the goals of these protected, “ecological savings accounts” are to serve as refuges for populations of fish, kelp, crabs, and other species to recover from exploitation, to allow older fish to reproduce and help sustain fisheries outside reserve borders, and to provide insurance against changing ocean conditions like those caused by climate change. For the past five years, researchers from around the central coast diligently surveyed the health of the ecosystems inside and outside the central coast MPAs. They measured abalone-like limpets clinging to rocks in the wave splashed intertidal, enlisted the help of volunteer anglers to catch and release fish, and explored the shadowy depths of the MPAs with submarines and camera-equipped robots hundreds of feet below the surface.

So far, their findings are promising. Many species, from black rockfish and lingcod to owl limpets and black abalone, have increased in abundance inside the new MPAs over the past five years. Some species of fish are also larger inside the protected areas, and these larger fish can produce more offspring. A report compiled by the California Ocean Science Trust summarizing these and other scientific findings of MPA monitoring is available as an interactive e-book on the new Ocean Spaces website. One of FISHBIO’S biologists also presented at the symposium, discussing her graduate research studying the feeding habits of gopher rockfish inside and outside of the central coast MPAs (see Gopher (rockfish) guts). These initial assessments of the MPAs are just a prelude of changes to come, as ecosystem recovery can take decades to occur. In addition to their ecological benefits, protecting special coastal places for their intrinsic value  makes economic sense. California’s renowned and much-visited coastline is a huge driver of the state’s ocean economy, worth about $42.9 billion (Kildow 2005). Some symposium speakers stressed that that the economic value of MPAs need be studied explicitly going forward. But from many angles, it appears that this investment in marine conservation is already paying off.

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Print This Post Print This Post
Conferences and Events, Ecology, Marine, Other Fish Species, Research

gopher rockfish preygopher rockfish

We know the importance of studying what fish eat when it comes to the feeding habits of salmon predators (see What’s for dinner, Last meal, Survival of the biggest). But did you know you can even get a graduate degree studying fish guts? That’s what one of our biologists did. She recently presented the results of her master’s thesis at the State of the California Central Coast Symposium on Marine Protected Areas in Monterey, sharing her research on the diet of the gopher rockfish (Sebastes carnatus). As you can see from the top photo, these fish scarf down quite a smorgasbord.

Gopher rockfish are one of about 60 different species of rockfishes in the genus Sebastes found on the California coast. Rockfish come in an array of colors and are known for their venomous spines, which can pack a stinging poke for an unwary angler. As generalist predators, gopher rockfish eat a diversity of other animals, from crabs, to worms, to fish. In this study, the gopher rockfish was used to study changes that might happen to the food web inside and outside of marine protected areas (MPAs) in central California. Results showed that gopher rockfish diets didn’t differ much inside and outside of these new MPAs, but fish caught at different locations along the coast ate different things. This is likely due to different habitats at these locations, ranging from Año Nuevo to Point Buchon near Morro Bay, which can result in differences in the invertebrate community. The gopher rockfish’s most important prey included brittle stars (a type of sea star), crabs, mysids, and shrimp (Loury 2011).

A gopher rockfish’s last meal is a bit like a window into the community where it lives, which is otherwise difficult to survey. Gopher rockfish often live in rocky holes – similar to a certain small mammal that shares their common name. While SCUBA divers can survey nearshore marine areas to count larger animals, they usually don’t count the many small critters hiding in cracks and crannies. A hungry gopher rockfish can more effectively “sample” these spots. Studying fish diet is a bit like being a detective or an archaeologist, and sometimes you make surprising discoveries (see Opportunistic Meal). The strangest thing found in a gopher rockfish stomach? A handful of strawberry sea anemones. Those might have been an accidental snack – the fish was probably after a brittle star lodged in the anemone clump.

Print This Post Print This Post
Conferences and Events

Come out and join us for the 4th annual Stanislaus River Salmon Festival this Saturday, November 3rd (10am-3pm), in the historic town of Knights Ferry, CA. The salmon are migrating up the Stanislaus in numbers we haven’t seen in years, so there should be good opportunities for salmon viewing. There will be activities for children of all ages, as well as food and live music. It’s sure to be a good time. Check out the Salmon Festival Facebook Page for updates and photos from past years.

Print This Post Print This Post
Conferences and Events

Today concludes World Water Week, held annually by the Stockholm International Water Institute. One of the seminars was titled, “Addressing the Water-Energy-Food Security Nexus: Challenges and Solutions in (International) River Basins”. The seminar focused on the Mekong Basin and similar systems where rivers and the resources they provide are shared by several nations. Water Week brings together high-level officials and CEOs from multiple sectors, including representatives from governments, financial institutions, industry, the sciences, and conservation groups. This unique forum highlights the many ways that water is integral to human health, economic growth, and biodiversity. For many of us around the world, we simply twist the tap and drinkable water flows. Who knows where it came from? Who knows where it’s going? Though some of us may take water for granted, it influences nearly every aspect of our lives. From the production of bottled beverages, to the cooling of industrial machinery, processing of fabrics, extraction of minerals, fisheries, production of electricity and timber; not to mention agriculture, transportation, recreation, and water for household cooking, cleaning, showering, and drinking; we use a lot of water for a lot of purposes. Apart from the obvious economic benefits to society, aquatic systems also hold their own inherent values, attracting us for their beauty and supporting a wide variety of organisms. As severe droughts are becoming more frequent across the U.S. and the world, perhaps water will be at the forefront of all our minds before long.