$1.4 Million Awarded to Six New Research Projects

Researcher:

Russ Moll, Ph.D
Director
California Sea Grant College Program
Scripps Institution of Oceanography
University of California, San Diego
E.: rmoll@ucsd.edu
T.: (858) 534-4440

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December 8, 2008

Sanderlings (foreground) and willets (the larger birds in the background) feed on intertidal animals that are disappearing from some sandy beaches. A new Sea Grant project will explore, among other things, processes altering foraging opportunities for shorebirds. Photo: David Hubbard

December 8, 2008

Contact: Christina S. Johnson, csjohnson@ucsd.edu, 858-822-5334

LA JOLLA – California Sea Grant has awarded $1.4 million to support six new marine research projects to begin in February.

The one-to-three-year-long projects, which include support for seven graduate students, address a breadth of important topics to California, including wetland restoration, beach preservation, invasive species control, plankton ecology, larval transport and sustainable aquaculture.

“Ecosystem-based management has become a central focus of the approach used by state and federal managers to protect our coastal ocean resources,” says California Sea Grant Director Russell Moll. “All of these new research projects employ an ecosystem-based approach in their investigations. We are pleased with the high quality of the projects and the promise of results directly applicable to ecosystem-based management of our valuable marine resources.”

Two of the six new projects will challenge and refine basic ideas about how the physics of the ocean drives its biology. One of these seeks to debunk the theory that invertebrate larvae are passive floats, dispersed by ocean currents. The findings will have relevance to, among other things, understanding larval transport and connectivity among marine reserves. The other project will examine whether small-scale, nearshore process (e.g., tidal flushing, waves, currents and mixing) might explain the formation of toxic algal blooms near the mouth of the Tijuana River in Imperial Beach.

Another project will probe the future of California’s sandy beaches in the face of rising sea levels and continued coastal population growth. Yet another will explore the feasibility and efficacy of releasing host-specific trematode parasites to cull burgeoning populations of the tiny invasive New Zealand mud snail.

The sole aquaculture project will tackle what is arguably the greatest obstacle to developing sustainable farming practices to meet global demand for seafood: reducing the amount of wild-caught fishmeal in commercial fish food. The goal of the project is to reduce fishmeal content of yellowfin and white seabass feed by 75 percent.

The new projects and their lead investigators are:

This site at the Tijuana River National Estuarine Research Reserve was cleared of tamarisk, but native plants are not re-growing in their place. A new Sea Grant project will examine why and what can be done. Photo: Christina S. Johnson/CSG

Making Tidal Wetland Restoration More Efficient: Testing Tamarisk’s Legacy Effects

Paul Dayton, UC San Diego and Theresa Talley, UC Davis

Southern California has lost most of its coastal wetlands, and much of the remaining habitat is very much altered by the presence of non-native plants, many of which are escapees of the ornamental plant trade. One such plant is the salt cedar tree, also known as tamarisk. Towering above native low-lying species, tamarisk shades succulents, accretes sediment and sheds woody debris, ultimately transforming rare wetland marshes into not-so-rare upland woods. Because of the ecological significance of coastal wetlands, managers at NOAA’s Tijuana River National Estuarine Research Reserve in San Diego are chopping down as many of the tamarisk trees as they can, in the hope that native plants will re-vegetate cleared areas. This project will examine whether this control strategy is effective, given that other invasive plants (e.g., giant reed, black locust and non-native cordgrasses) re-engineer their physical surroundings, thwarting native re-growth. Scientists will conduct field experiments at the Tijuana River reserve to answer whether tamarisk leaves similar “legacy effects.” If so, they will explore options for undoing them. It is hoped that what is learned will help the reserve improve ongoing wetland restoration cost effectively.

Beaches as Threatened Ecosystems: Evaluating Trends

Jenifer Dugan and Adrian Wenner, UC Santa Barbara, and David Revell, UC Santa Cruz

California’s beaches are often framed in terms of their value to recreation and tourism. Less appreciated is that these land-sea boundaries are also important habitats to an amazing diversity of invertebrate, bird and marine life. What, though, is the fate of California’s beloved beaches in the face of rising sea levels and continuing population growth? An interdisciplinary team of scientists will address this topic by compiling several historical datasets and re-sampling several historical study sites. From this, they will construct a 30-year history of the ecology and physical characteristics of the sandy beaches between Morro Bay and San Diego. They will then analyze this record to look for meaningful trends that might explain processes affecting sand supply, beach width, biological diversity and community structure. The historical record will also be analyzed to look for potentially rare, declining or even locally extinct intertidal species that may be important prey items for birds and other higher trophic level organisms. The findings will be shared with managers to improve beach management and conservation.

Tiny, prolific New Zealand mud snails can comprise 95 percent of a river’s invertebrate biomass. Sea Grant scientists are investigating whether snail parasites might offer a biological control strategy for this invasive species. Photo: Dan Gustafson / Montana State University

Could the Release of Snail Parasites Halt the New Zealand Mud Snail?

Thomas Dudley, UC Santa Barbara, Kevin Lafferty, USGS, and Armand Kuris, UC Santa Barbara

The ultimate goal of this project is to investigate the feasibility of releasing parasites to control New Zealand mud snail populations in the Great Lakes and Western states, including California, where the snail has invaded the American River, Lake Shasta, Alameda, Piru and Malibu creeks, among others. In the first year of the project, scientists will test the host specificity of the trematode parasites they hope to release to ensure their safety to native species. In other words, they want to rigorously verify that the parasites won’t infect native snails. They will also determine whether the parasites, a type of castrator, curb invasive mud snail population growth enough to warrant their release. Field experiments will be conducted in California and also in the mud snail’s native New Zealand habitat.

Linking Freshwater Inputs with Nearshore Plankton Ecology

Falk Feddersen, Peter Franks and Robert Guza, UC San Diego

The Imperial Beach 2009 experiment will study the complex set of physical processes controlling water quality during the warm, dry season, when people are most likely to come in contact with contaminated beach water. The specific goals of the project:

1) Determine where nearshore nutrients are coming from and how these sources relate to nearshore phytoplankton “patchiness” and episodic blooms, including harmful algal blooms.
2) Quantify the effects of nearshore conditions (i.e., tides, waves, currents and mixing) on distributions of phytoplankton and fecal indicator bacteria.
3) Quantify the relative concentrations of free-living fecal indicator bacteria and diagnose the conditions under which they attach to phytoplankton. Determine whether attachment affects rates of bacterial loss.
4) Address the degree to which sunlight and dilution reduce viable fecal indicator counts in the surfzone.

Stylized images of shore crab postlarvae, Pachygrapsus crassipes (left) and Hemigrapsus nudus (right). California Sea Grant biologists believe that larvae and postlarvae control their depth in the water column, which, in turn, determines the distance that they disperse from parents. Photo: Jennifer Fisher, UC, Davis

Understanding Invertebrate Larval Transport

Steven Morgan and John Largier, Bodega Bay Marine Laboratory, UC Davis

Contrary to prevailing view, invertebrate larvae are not swept hither and yon by ocean currents, the scientists leading this project report. Instead, surprisingly, they appear to exert considerable control over their movements and usually remain near shore, even during strong upwelling events. In this project, scientists will continue to scrutinize the degree to which ocean currents can be viewed as a forcing mechanism for larval transport and settlement. In the project’s first year, larvae will be surveyed at two locations with persistent upwelling, including Point Arena, the strongest upwelling center in California, and Bodega Head. The findings will add to what is known about larval transport mechanisms, connectivity and self-recruitment, and the role of physical forcing on larval supply.

Thirty-six percent of all wild-caught fishes are used to feed animals. A Sea Grant project will seek to develop a fish feed with 75 percent less fishmeal. Photo: Fisheries and Oceans Canada

Reducing Fishmeal in Aquaculture Feeds

Mark Drawbridge, Hubbs-SeaWorld Research Institute, Frederic Barrows, Fish Technology Center at USDA, and Ronald Hardy, Aquaculture Research Institute, University of Idaho

The overall goal of this project is to reduce the amount of fishmeal and fish oil in yellowtail and white seabass feeds, without impeding fish growth rates or otherwise compromising fish health. In the first phase of the project, scientists will develop a replacement protein based on a combination of fishmeal alternatives such as soy, canola, corn, barley, poultry-by-product meal and blood meal. Scientists will experiment with adding mineral supplements to compensate for fishmeal losses. These “protein shakes” will be added to feeds at graded levels to progressively reduce fishmeal content. Once appropriate protein sources, amino acid balances, and mineral supplements are determined, scientists will conduct experiments to optimize the feed’s protein to energy (calorie) content. They will then begin investigating alternatives to fish oil. It is hoped that the project will result in commercially viable fish feeds with 75 percent less fishmeal and 50 percent less fish oil.