Posts Tagged California Sea Grant

Aug 4 2015

Climate Change Causes Timing Shifts in Fish Reproduction | Scripps Institution of Oceanography, UC San Diego

Photo of mackerel
Warmer ocean temperatures affect seasonal cycles

Research by Rebecca Asch, a recent graduate of Scripps Institution of Oceanography at UC San Diego, shows a strong correlation between warmer ocean temperatures and changes in the timing of fish reproduction.

The study, “Climate Change and Decadal Shifts in the Phenology of Larval Fishes in the California Current Ecosystem ,” was published in the July 9 early edition of the Proceedings of the National Academy of Science.  This is the first study to examine the effects of temperature, upwelling, and abundance of zooplankton on fish phenology in the Southern California Current ecosystem.

Climate variability has changed the seasonal cycle of larvae production by fishes in the California Current.  Such shifts in seasonal, biological processes are known as phenology. Changes in phenology are studied by scientists as a key way to assess the effects of climate change on a species.

There have been extensive studies on the phenology of terrestrial (land) species, but comparatively few studies on how climate variability affects seasonal behavior of marine species. Existing studies indicate that changes in seasonal cycles are occurring earlier in most terrestrial ecosystems. Climate change may cause the phenology of marine animals to change more rapidly than terrestrial species.

Unseasonably warm ocean temperatures may also affect migration patterns, bringing several marine species usually found in regions closer to the Equator closer to Southern California.  In February, a pod of false killer whales were seen from the Scripps Pier; this was the first time these whales have been seen north of central Baja California.

Asch studied the larval stages of 43 fish species that were collected off the Southern California coast between 1951 and 2008.  The research used the larval fishes from the California Cooperative Oceanic Fisheries Investigations (CalCOFI), a unique data set that has been consistently collected and maintained for over 60 years; it is among the oldest and most complete datasets of its type.

The data showed that many fish species spawned earlier, other species showed no long-term change in spawning cycles, and a few species spawned later.  Many of the species with no long-term changes in spawning show variations in spawning between years, indicating that the changes in their spawning cycles may have occurred due to factors other than climate change, such as naturally occurring climate variability.

Asch’s findings may also be useful for fisheries management. “The fishes are reacting to climate change and it will be important for any fisheries management with a seasonal component to adapt their practices to avoid mismanagement,” she said.

The Southern California Current is an example of an Eastern Boundary Current Upwelling (EBCU) ecosystem.  These ecosystems account for over twenty percent of global fish catch.  If the California Current is representative of other EBCU ecosystems, similar changes in fish phenology to ones observed by Asch could be occurring around the world.

A change in the time of year when fish reproduce can affect their overall ecology. Generally, fish reproduce during seasons when there is an abundance of zooplankton and/or when upwelling is minimal.  This behavior maximizes the survival of larvae and prevents larvae from being swept into unfavorable habitats by currents. Unlike fishes, zooplankton have not exhibited continuous changes in phenology over the 60-year period of the CalCOFI program.  Over time, this “mismatch” between the seasonality of larvae and zooplankton could cause fish species to potentially spawn during less than ideal periods for larvae survival.

The study was funded by California Sea Grant, NOAA’s Nancy Foster Scholarship Program, NSF IGERT Grant, the San Diego ACRS Foundation, and the Nippon Foundation.

Read the original article:

Sep 19 2013

Fishermen now the “right hand” of marine research

Sea Grant CA
Bycatch reduction, gear recovery and direct-seafood marketing are among the topics currently addressed through collaborative research with commercial and recreational fishermen.

Other projects examine rockfish populations within the Rockfish Conservation Areas; yellowtail movement patterns in Southern California, and spawning populations of night smelt along the North Coast.

All of the projects are unique in that fishermen are in some way directly involved with the research. They may have initiated the project’s basic concept, or they may be helping to collect data. In some cases, they are also helping analyze it. The unifying theme is that both anglers and commercial fishermen are engaged in work that often, previously has been isolated within academic or management circles.

California Sea Grant supports this innovative research through our partnership with the non-profit Collaborative Fisheries Research West, funded by the California Ocean Protection Council. California Sea Grant Extension specialists are lead investigators on several of the projects, as well.

The 12 projects listed below include both large, multi-year grants, with awards ranging from $206,000 to $242,000 plus matching funds, and mini grants, with awards at or below $25,000 plus matching funds.

Read the full article here.

Apr 19 2012

Online Report: Profiles of North Coast Fishing Communities

Charter boats at Trinidad dock Photo: C. Pomeroy

By: Caroline Pomeroy, Cynthia J. Thomas and Melissa M. Stevens

LA JOLLA, CA – California Sea Grant is pleased to announce the availability of an online edition of “California’s North Coast Fishing Communities: Historical Perspective and Recent Trends.”

The 340-pp. technical report presents a historic, demographic and economic overview of the region’s four major fishing communities: Crescent City in Del Norte County, Trinidad and Eureka/Fields Landing in Humboldt County, and Noyo/Fort Bragg in Mendocino County.

Profiles of each community highlight major commercial and recreational fisheries, their values, fleet sizes and how they have changed over time. There is also key information on fishing infrastructure – such as docks, piers, slips, launch ramps and cold storage facilities – and market channels for local commercial catches. But perhaps the most interesting sections are those that describe the current challenges and outlooks for sustaining the fishing communities.

The report was prepared originally, with funding from the California Coastal Conservancy and NOAA Fisheries in 2010 as a resource for addressing a diversity of fishery management and policy issues. It has since been used to inform local decision-making and to evaluate some of the potential social and economic consequences of establishing marine protected areas along the North Coast.
Sorting fish at Caito Fisheries in Fort Bragg. Photo: C. Pomeroy

“It (the report) is an invaluable reference for fielding public and media requests about local fishing, because it explains the value of our fisheries to the overall port community,” said Dan Berman, Director of the Conservation Division for the Humboldt Bay Harbor, Recreation and Conservation District.

“We know what is going on at our docks,” said Eureka-based fisherman Dave Bitts, president of Pacific Coast Federation of Fishing Associations and one of the more than 180 fishery participants interviewed for the project. “What the report has done is assemble our knowledge in a way that is accessible to academics, consultants and government workers.”

Fisheries managers, both state and federal, are required to consider the social and economic impacts of regulations. “Yet, in-depth social science information on California fishing communities has been quite scarce,” said Caroline Pomeroy, a California Sea Grant marine advisor based in Santa Cruz and the lead author of the report, explaining her motivation for pursuing the research.

The full reportexecutive summary and individual community profiles can be downloaded at the California Sea Grant Extension web page or through the University of California’s eScholarship open-access repository.

California Sea Grant is part of NOAA’s National Sea Grant, a network of 32 university-based programs.