the partnership for interdisciplinary studies of coastal oceans · 2017-06-01 · ocean warming may...

what is PISCO?The Partnership for Interdisciplinary Studies of Coastal Oceans is a long-term program of scientifi c research and training dedicated to advancing the understanding of the California Current Large Marine Ecosystem along the U.S. West Coast. PISCO is pioneering an integrated approach to studying this complex, rich, and economically important environment.

PISCO is distinguished by its interdisciplinary approach, large geographic extent, and decades-long time frame. PISCO conducts monitoring and experiments along more than 1,200 miles (2,000 kilometers) of coastline, as well as laboratory and theoretical studies. The research incorporates oceanography, ecology, chemistry, physiology, molecular biology, genetics, and mathematical modeling to gain novel insights into systems ranging from individual animals and plants to the whole ecosystem.

PISCO’s fi ndings apply to conservation and resource management issues. PISCO scientists participate in local, regional, national, and international initiatives for marine environmental planning. Through its university courses, PISCO helps to train the next generation of scientists in interdisciplinary approaches to marine research and policy.

Established in 1999 with funding from The David and Lucile Packard Foundation, PISCO is led by scientists from Oregon State University (OSU), Stanford University’s Hopkins Marine Station, University of California at Santa Cruz (UCSC), and University of California at Santa Barbara (UCSB). As of 2005, core PISCO activities are funded by collaborative grants from The David and Lucile Packard Foundation and the Gordon and Betty Moore Foundation. The core support and additional funding from diverse public and private sourcesmake this unique partnership possible.

1 View from the Wave Crest

2 Patterns of ChangeMolecular EcologyArrival of Young Reef Fish Abalone Disease Spreads

6 Oceanographic FrontiersReturn of the Dead ZoneEddies Fertilize KelpPlankton Ride the Currents

10 Ecological LinkagesLinks Among Populations Sea Star Boom and BustLimits of Seaweed Growth

14 Interdisciplinary Training & Research

PISCO Offers New CoursesInterdisciplinary Student

Research

16 Sharing the ScienceMarine Reserves and

FisheriesScience Videos Released

View from the Wave Crest

PISCO Coastal Connections Program Coordinator: Kristen MilliganPISCO Coastal Connections Coordinators:Satie Airamé, Liz Riley, Cinamon S. Vann

Editor & Writer: Peter H. TaylorCreative Director: Monica PessinoSenior Designer: Natalie WongGIS Support: Will McClintockLine Drawings: Linda D. Nelson

Cover photo: PISCO/UCSB researcher Jenn Caselle © 2005 Michael Sheehy. Cover photo insets, top to bottom: LaTisha Hammond, Cascade Sorte, Ralph Clevenger, Jane Lubchenco. Opposite page photos, left to right: Gretchen Hofmann, Ralph Clevenger, Melissa Foley, Gretchen Hofmann

PISCO Coastal Connections is a publication of the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO). Contents © 2005.For more information about PISCO or to join the mailing list for future publications, please contact the consortium at the addresses listed on the back cover.

PISCOCoastal ConnectionsVolume 4

Table of Contents Welcome to the fourth issue of PISCO Coastal Connections, an annual publication of the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO). Our large-scale and long-term interdisciplinary marine research program is celebrating fi ve years of continued success. There has been a rapid expansion of research based on signifi cant discoveries, an increased number of researchers, and high demand from policy makers and resource managers for information.

With new funding from The David and Lucile Packard Foundation and the Gordon and Betty Moore Foundation, we have an exciting opportunity to continue to expand our knowledge of the marine ecosystem, train the next generation of scientists, and effectively inform policy.

This issue of PISCO Coastal Connections highlights major fi ndings of the past PISCO Coastal Connections highlights major fi ndings of the past PISCO Coastal Connectionsyear. PISCO’s scientifi c research focuses on the highly productive and diverse California Current Large Marine Ecosystem. “Patterns of Change,” “Oceano-graphic Frontiers,” and “Ecological Linkages” describe new scientifi c advances and insights into how this marine system functions. “Interdisciplinary Training” introduces expanded course offerings and showcases student research that crosses disciplinary boundaries with invigorating results. “Sharing the Science” illustrates some of our work to improve science-based management of coastal systems and to communicate PISCO science to other researchers, the public, and the management community.

We invite you to enjoy this issue of PISCO Coastal Connections and the PISCO Coastal Connections and the PISCO Coastal Connectionsachievements described on the following pages.

PISCO principal investigators (left to right): Steve Gaines (UCSB), Libe Washburn (UCSB), Mark Carr (UCSC), Pete Raimondi (UCSC), Jack Barth (OSU), Gretchen Hofmann (UCSB), Margaret McManus (UCSC), Jane Lubchenco (OSU), Mark Denny (Stanford), Bruce Menge (OSU), George Somero (Stanford), Steve Palumbi (Stanford), and Robert Warner (UCSB). Photo: Satie Airamé

PISCO Coastal Connections • Volume 4

1

OFpatterns change

Snails (Nucella species)

Purple sea urchin


Physiological Responses to

Ocean Warming

PISCO/UCSB graduate student Cascade Sorte found that marine snails (Nucella species) living in California—the southern edge of their geographic range—are stressed by the relatively warm waters. This causes them to produce more heat-shock proteins than snails living in Oregon’s cooler climate, which is the center of their geographic range. Ocean warming may force the southern edge of the snail’s geographic range to recede to the cooler waters in the north. Colors correspond to sites on map.Photo: Sheri Etchemendy

PISCO/UCSB graduate student Chris Osovitz found that purple sea urchins (Strongylocentro-tus purpuratus) living in the cool climate of Or-egon (blue bars) began to produce heat-shock proteins at lower temperatures than urchins living in the warmer climate of southern Cali-fornia (yellow bars). If ocean temperatures rise rapidly, Oregon urchins are more likely to be vul-nerable to thermal stress than California urchins. Photo: Gretchen Hofmann

Geographic Variation in Urchin Stress Responses

Geographic Variation in Snail Stress Responses

arine ecosystems are experiencing crises worldwide, espe-cially in coastal waters, as animals and plants endure the physiological stress of environmental changes, such as ocean warming. To understand these stresses, PISCO/UCSB principal investigator Gretchen Hofmann is pursuing a new,

integrated approach that combines molecular biology with ecology, ocean-ography, and geography. How do physiological traits in marine species vary along hundreds of miles of the U.S. West Coast? How does temperature infl uence the physiology of invertebrates and algae and help to set their geographic range boundaries? Do marine animals and plants have the physi-ological resiliency to survive the rapidly changing environment? The integra-tive research by Hofmann and her graduate students (see examples below) is providing novel insights into fundamental ecological processes and man-agement issues. By applying new molecular techniques to marine research, they are revealing how species’ geographic ranges might shift in the face of climate change.

Gene-ography?Molecular biology and ecology on a geographic scale

M

PISCO/UCSB graduate student Sarah Henkel (below, left) is studying geographic differences in the growth form, genetics, and temperature tolerances of feather boa kelp (Egregia menziesii) from Oregon to southern California. She is investigating the geographic ranges of genotypes along the coast and gene fl ow among the populations. She will determine how genetic differences may affect survival of kelp in different water temperatures.

PISCO/UCSB graduate student Jessica Dutton (below) is compar-ing the physiologies of an invasive mussel (Mytilus galloprovincialis) and a native mussel (M. trossulus) to determine if the invader has greater tolerance for temperature stress. She has found that both the geographic location between south-ern California and Alaska and the position within a site can infl uence production of heat-shock proteins in mussels. Dutton is relating differ-ences among sites to thermal and oceanographic conditions.

PISCO/UCSB graduate student Mackenzie Zippay (below) is exploring the potential impacts of a warming climate on survival of marine snail (Nucella) larvae. Using molecular techniques and incuba-tion experiments, she is assessing the effects of temperature on the young of fi ve snail species, which are more sensitive to heat than the adults. Her research probes how the changing survival rates of young snails due to climate change might infl uence the geographic range of adults along the U.S. West Coast.

Gretchen Hofmann with students. Photo: LaTisha Hammond

Nucella lays eggs. Photo: Gretchen Hofmann

Gene-ography in action

Photos: Gretchen Hofmann


3

Partnership for Interdisciplinary Studies of Coastal Oceans

Population Replenishment of Reef FishAs part of PISCO’s kelp forest monitoring program, led by PISCO/UCSC princi-pal investigator Mark Carr and PISCO/UCSB science coordinator Jenn Caselle, divers count young rockfi sh and kelp bass each year at sites from Monterey Bay to the Channel Islands. These summer surveys of ecologically and eco-nomically important species provide scientists and managers with a large-scale, long-term perspective on the distribution and year-to-year changes in popula-tion replenishment.

Conducted since 1999, the surveys reveal interesting geographic patterns and changes over time (see fi gure, below). Kelp forests located near each other, such as the Hopkins and MacAbee sites in Monterey Bay, tended to have simi-lar trends in their numbers of young rockfi sh (red and pink lines on graphs). More distant sites, such as Sandhill Bluff (purple lines), had different trends.

On a regional scale, kelp forests located at, above, and below Point Concep-tion displayed distinct trends in fi sh population replenishment. For example, young kelp bass occurred only at southern sites, but these sites had few young rockfi sh. Conversely, sites north of Point Conception had greater number of young rockfi sh, but young kelp bass have not been encountered during surveys at these sites.

These fi ndings suggest that coastal currents strongly infl uence patterns of reef fi sh population replenishment. To understand these local- and regional-scale linkages, PISCO is conducting ongoing studies using oceanographic instru-ments and devices that collect young fi sh (see cover photo and PISCO Coastal Connections, Volume 2). Information from this research informs the design and evaluation of marine reserves and other management efforts.

The More, the Munchier

Adult rockfi sh live in kelp forests and generally do not swim great distances, but their young drift with currents, possibly many miles. The number of young arriving into a local population can vary greatly from year to year. Field experiments by PISCO/UCSC graduate student Darren Johnson revealed that when juvenile kelp rockfi sh arrive in large numbers, their rate of mortality increases. The higher mortality likely arises from predators preferentially consuming more young when the young are plentiful. Johnson uncovered a similar pattern when he analyzed data from PISCO’s yearly counts of rockfi sh in California kelp beds. His fi ndings indicate that the number of young rockfi sh arriving at a kelp bed may not be directly proportional to the future number of adults. Johnson is exploring how the effect may differ among sites due to predator abundance and habitat complexity.

Darren Johnson is now a doctoral student at Oregon State University.

Kelp rockfi sh (Sebastes atrovirens). Photo: Darren Johnson

Gopher rockfi sh (Sebastes carnatus). Photo: Ralph Clevenger

Numbers of young fi sh in California kelp forests


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patterns of change

Abalone Disease Spreads Northward Historically, the black abalone was one of the most important herbivores in the intertidal zone along much of the U.S. West Coast. In the mid-1980s, however, the species began suffering mass mortalities from a disease called “withering syndrome,” which shrivels the abalone’s foot until it can no longer adhere to the substratum. The fi rst die-offs occurred at the Channel Islands in 1986, and the disease progressed northward until reaching the south-ern boundary of the Monterey Bay National Marine Sanctuary by 2001 (see fi gure). Since then, large, healthy populations of black abalone have existed only in the Sanctuary, apparently because the cool waters in this region kept the incidence of disease low.

PISCO/UCSC principal investigator Pete Raimondi and his research group identifi ed three possible reasons that populations are not replenished after they crash: (1) dispersal from elsewhere is limited, (2) disease is still present, and/or (3) the habitat is fundamentally altered by absence of abalone. All three poten-tial explanations have important implications for management and conserva-tion of this species. The third is particularly worrisome because it suggests that natural recovery likely would be very slow.

After northward progress of the pathogen seemed to halt around 2001, the scientists hypothesized that the cooler northern waters might prevent further spread. However, the fall 2003 survey revealed population declines at the Sanctuary’s southern end, which had never happened before. Whether this represents a renewed northward spread of withering syndrome remains to be seen. However, the declines clearly indicate a need for ongoing and perhaps expanded monitoring of black abalone numbers because the remaining healthy populations are severely restricted. The occurrence, extent, and eco-logical consequences of black abalone die-offs would not have been identifi ed without the large-scale, long-term monitoring program conducted by PISCO, Minerals Management Service, and their partners.

Limpets in the Limelight

In experiments in the low intertidal zone along the Oregon coast, PISCO scientists Tess Freidenburg and Patricia Halpin and PISCO/OSU principal investigator Bruce Menge found that the impacts of limpet grazing on algae varied depending on regional oceanographic conditions. Effects of limpet grazing were greater in a region of higher phytoplankton productivity than a region of lower productivity. The causes underlying the regional differences are unclear, leading the scientists to conclude that more studies of limpet reproduction and population replenishment in these regions are needed to understand the shoreline ecology.

Patricia Halpin is now an assistant research biologist at the University of California, Santa Barbara.

PISCO scientists have documented the spread of abalone “withering syndrome” northward from the Santa Barbara area in recent years. Black abalone populations at southern sites (red dots), such as Site C (bottom graph), crashed after outbreaks of the disease. Light blue dots indicate sites at the southern end of the Monterey Bay National Marine Sanctuary where black abalone numbers were stable until 2003. That year, PISCO’s monitoring program revealed a sharp decline in adult and, in particular, young black abalone at these sites (Site B, middle graph), suggesting that withering syndrome might be spreading north into the Sanctuary. At northern sites (dark blue dots), such as near Site A (top graph), black abalone had not declined as of 2003. Photo: Megan Williams

Shield limpet (Lottia pelta). Photo: Roly Russell

Black abalone


5

oceanographicfrontiers

In 2004, a swath of oxygen-poor water near the Oregon coast caused widespread die-offs of marine life. Dungeness crabs killed by lack of oxygen washed ashore in great masses (left), providing an unusual feast for ochre sea stars (right). Photos: Elizabeth Gates (left), Jane Lubchenco (right)

Towing an oceanographic sensor through the water, PISCO researchers tracked the location and severity of the “dead zone” near Oregon’s coast during the summer of 2004. This fi gure shows the deep, oxygen-poor water along the seafl oor within three kilometers of the coast.


Hypoxia Grabs Headlines

The reappearance of a dead zone along Oregon’s coast in 2004 (see main article) attracted signifi cant local and national media coverage, resulting in more than a hundred newspaper and Web articles. National Public Radio reporter Christo-pher Joyce interviewed PISCO researchers onboard PISCO’s research vessel, the R/V Elakha, for a story that aired on All Things Considered. Associated Press reporter Jeff Bernard and Science magazine reporter Bob Service also joined a research cruise aboard the Elakha to investigate the oxygen-poor zone. Their articles appeared in newspapers across the country and in Science magazine. In addition, Portland’s KGW television station visited Oregon State University to interview PISCO scientists about the phenomenon. PISCO’s policy and outreach team continues to provide information about the dead zone to journalists, scientists, and others all over the world.

On PISCO’s research vessel R/V Elakha, Christopher Joyce of National Public Radio records a report on hypoxia. Photo: Jane Lubchenco

Return of the Dead Zone

O xygen-poor water fi rst appeared in 2002 along Oregon’s coast, killing crabs and fi sh by the thou-sands (see PISCO Coastal Connections, Volume 2). A change in ocean circulation appar-ently was the primary trigger, but scientists were not sure if it was a fl uke or a long-term trend.

In 2004, the unusual dead zone reappeared, and PISCO scientists collabo-rated with the National Oceanic and Atmospheric Administration (NOAA), Oregon state agencies, the University of Washington, and OSU’s College of Oceanographic and Atmospheric Sciences to track the swath of oxygen-poor, or hypoxic, water. Between June and September, the mass of hypoxic water spanned several hundred square kilometers and caused signifi cant mortality of Dungeness crabs, an ecologically and economically important species on the Oregon coast. The PISCO/OSU team—led by postdoctoral fellow Francis Chan, graduate student Anthony Kirincich, and principal investigators Jack Barth, Jane Lubchenco, and Bruce Menge—collected data that indicated that a two-step process caused the dead zone. First, strong, summertime winds pulled deep, oxygen-poor but nutrient-rich water toward the coast. In turn, the nutrient-rich water fueled blooms of phytoplankton that sank to the seafl oor, where the phytoplankton decomposed and further lowered oxygen levels. In 2002, the upwelled water was exceptionally cold, low in oxygen, and high in nutrients—conditions that seem to have reoccurred to a lesser degree in 2004. The measurements hint that a fundamental shift in ocean circulation may be under way. Will the dead zone become a regular seasonal visitor, and how will it affect Oregon’s rich coastal ecosystem? PISCO’s long-term interdisciplinary research program will help to provide answers.

Sea stars feed on crabs killed by the oxygen-poor water of the dead zone. Photo: Jane Lubchenco


77

Eddies Fertilize Kelp BedsDuring summer, growth of giant kelp in the Santa Barbara Channel is often limited by nutrients. PISCO/UCSB graduate student Corinne Bassin and princi-pal investigator Libe Washburn have discovered an oceanographic circulation pattern that delivers much-needed nutrients to kelp beds, helping to sustain their growth and survival. Using high-frequency radar, Bassin and Washburn collected detailed data on surface currents over several years in the western Santa Barbara Channel. Analysis of the data revealed that small eddies fre-quently form in at least three places along the mainland. Lasting an average of two days, the eddies range in diameter from four to fifteen kilometers. When the eddies spin along the coast, they bring cooler water and higher concentrations of nitrate—an essential nutrient for kelp. Previously unrecog-nized, these oceanographic features may serve a critical role in enabling kelp beds to thrive.

On December 11, 2001, high-frequency radar revealed an eddy rotating clockwise along the coast near Santa Barbara, California. The eddy brought cold, nutrient-rich water to kelp beds near shore. On prior and following days, when the eddy was not present, water temperature rose and nitrate levels dropped. In the figures, arrows show surface currents, and colors indicate the strength of rotation of eddies. Blue shades indicate clockwise rotation, and red shades are counterclockwise.

Giant kelp in the Santa Barbara Channel. Photo: Laura Francis

A diver retrieves instruments that were deployed in the Santa Barbara Channel. Photo: Brent Mardian

These instruments measure temperature, salinity, chlorophyll, and water clarity. Photo: Brent Mardian


8


oceanographic frontiers

Plankton Retained in Thin LayersIn the ocean, plankton are often concentrated in thin layers that range in thickness from centimeters to a few meters (see PISCO Coastal Connections, Volume 3). Densities of plankton within the layers are three to five times greater than in water above and below, and the layers may extend horizon-tally for kilometers and persist for days. PISCO scientist Margaret McManus and several colleagues conducted a four-week study in Monterey Bay to investigate the significance of thin layers in the ecology of coastal waters. The scientists found that the plankton thin layers tended to occur at depths with minimal currents. As shown in the figure below, the plankton thin layers were sand-wiched between currents flowing toward shore and away from shore. These findings suggest that thin layers may strongly influence the movement of larval fish and invertebrates, harmful algal blooms, and marine viruses and bacteria near shore.

Water Depth Controls Strength of Offshore FlowResearch by PISCO scientists Anthony Kirincich and Jack Barth has revealed an important oceanographic influence on the ecology of Oregon’s coastal waters. Using five years of data from moored sensors, the scientists found that wind-driven currents moving away from the coast are four times weaker over the inner shelf (at water depth 15 meters) than they are farther offshore over the outer shelf (water depths greater than 50 meters). These cross-shelf currents further diminish in strength when storms mix the coastal water and reduce the water’s stratification. Such changes in current strength could affect the movements of fish and invertebrate larvae and the delivery of nutrients to seaweeds and phytoplankton. For example, weak currents may retain barnacle larvae near shore, helping them to settle into coastal habitats. Now Kirincich and Barth are investi-gating differences among sites in the effects of stratification and the pos-sible impacts on dispersal of larvae.

Study area at Monterey Bay, California.

PISCO scientists discovered a thin layer (indicated by dots) of highly concentrated zooplankton at ten- to fifteen-meter depths in Monterey Bay, California. Currents moving toward the shore are indicated with yellow, orange, and red. Currents moving away from shore are shown as blue colors. The depth of the thin layer varied over time, and it was sandwiched between the onshore and offshore currents.

Along the Oregon coast, winds often cause the surface water to flow offshore. PISCO scientists found that the strength of this flow increases dramatically over the inner continental shelf (water depth 50 meters or less) and then remains constant over the outer shelf (top purple arrow). At the same time, deep water moves along the seafloor toward the coast, but this flow weakens across the inner shelf (bottom purple arrow).

Anthony Kirincich services an instrument.Photo: Bob Service


9

PISCO Coastal Connections • Volume 4linkagesecological

Using a combination of microchemistry and ecology to track birthplaces of rockfish, PISCO scientists continue to better define connections among rockfish populations. The graph above shows the natural chemical signatures in the ear bones, or otoliths, of rockfish. Newly settled young rockfish, called recruits, collected at Santa Cruz Island had signatures similar to those of rockfish larvae from the island (red dots) but not larvae from the mainland (green dots). These results indicate that few young rockfish from the mainland settled at Santa Cruz Island.

Otolith Signatures in Rockfish

Connections among

Kelp rockfish larvae(4.6 mm)

Young kelp rockfish(14.8 mm)

Rockfish Populations

Study Sites


How Are Fish Populations Linked?

A central goal of PISCO’s research program is to understand how populations of marine fish and invertebrates are interconnected. The young of most species potentially could drift many miles before settling down into adult life. Understanding

where the young go and where the adults come from is invaluable for developing fisheries management and marine conservation strategies. Because tracking the tiny young as they disperse is not feasible, PISCO is developing innovative methods that take advantage of natural “flight recorders” in the animals’ bodies. The methods involve analysis of environmental chemical signatures recorded in the inner ear bones, or otoliths, of fish as they grow (see PISCO Coastal Connections, Volumes 1, 2, and 3).

PISCO/UCSB doctoral student Julie Standish and principal investigator Bob Warner conducted experiments at the Channel Islands and the nearby mainland to test whether the “flight recorders” could be used successfully to determine the birthplaces of rockfish and the connections among rockfish populations. At three sites on Santa Cruz Island and one site on the mainland, Standish and Warner analyzed otoliths from recently arrived, young rockfish and from newborn rockfish larvae that had not yet dispersed. They found that the chemical signatures in otoliths of the recently arrived rockfish at the island were similar to those of larvae collected at the island, but not to those of larvae collected at the mainland (see figures, opposite). The results indicate that of the young rockfish found at the island, only a few—less than two per-cent—had been born at the mainland site. Based on this study, it appears that populations of rockfish at Santa Cruz Island are not linked strongly to mainland populations. (The number of young rockfish that settled along the mainland was so small that their otoliths were not analyzed in the study.) Standish and Warner’s work demonstrates the promise of the “flight recorder” technique for understanding ecological connections—and lack of connections—among marine populations.

Embryos of the alga Silvetia compressa. Photo: Cynthia Hays

Cynthia Hays collects a sample of Silvetia algae.Photo: Jim MacKenzie

Julie Standish examines the layers of a magnified otolith, or ear bone, of a rockfish. Photo: Jeff Barr

Gene Flow and Local Adaptationin a Seaweed

Because many marine species have offspring that potentially disperse long distances, their ability to adapt to local conditions has been uncertain. PISCO/UCSC doctoral student Cynthia Hays con-ducted one of the first experiments ever to show genetic adaptation of a marine species over short distances. She focused on a common alga called Silvetia that lives on rocky shores, where risks of extreme temperatures, desiccation, wave damage, and other factors can vary radically within meters. Hays’s study reveals that Silvetia offspring typically disperse less than two meters and that individuals display remark-able local adaptation. For example, indi-viduals from different study sites differed in the upper and lower heights where they could survive on the shore, and their offspring differed in their tolerance of des-iccation stress. Within some sites, adults and offspring were adapted specifically for particular heights on the rocks. Hays’s findings demonstrate, for this marine spe-cies, that gene flow does not prevent local adaptation.

11

Partnership for Interdisciplinary Studies of Coastal Oceans PISCO Coastal Connections • Volume 4

Nutrient Supply Affects Seaweed DiversityFormer PISCO/OSU graduate student Matt Bracken’s research provides insight into the factors infl uencing diversity of seaweeds living on rocky shores. Work-ing with Karina Nielsen (see related article, page 13), he studied the effects of nutrient supply on the number of seaweed species living in tide pools on the Oregon coast. Because tide pools receive nutrients when fl ooded by the tides, seaweeds living in high-zone pools receive fewer nutrients than those living lower on the shore. Seaweeds require these nutrients for growth, so a scarcity of nutrients can limit the number of seaweed species that survive in a tide pool. Bracken and his collaborators found that nutrient stress in many high-intertidal pools is alleviated by the excretion of nutrients by mussels, sea anemones, and other invertebrates. As a result, the number of seaweed spe-cies in a given pool is closely associated with the rate of nutrient supply from invertebrates. The study also revealed that when more seaweed species live in a tide pool, they are more effi cient at using limiting nutrients. The fi nding of a reciprocal relationship between seaweed diversity and nutrient availability illustrates the importance of biodiversity in marine ecosystems: Not only do nutrients infl uence seaweed diversity, but more diverse seaweed assemblages are more effective at absorbing limiting nutrients.

Matt Bracken is now a postdoctoral researcher at the Bodega Marine Labora-tory of the University of California, Davis. Matt Bracken surveys seaweed diversity in tide pools at

Strawberry Hill, Oregon. Photo: Cascade Sorte

Increase in Seaweed Diversity with Nutrient Supply

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Partnership for Interdisciplinary Studies of Coastal Oceans PISCO Coastal Connections • Volume 4

ecological linkagesSea Star Boom and Bust

During the El Niño of 1997–98, sea star populations in the Channel Islands crashed, as the warmer water fueled an epidemic of “wasting disease” that disintegrated the animals. Between 1999 and 2004, however, PISCO/UCSB scientists Carol Blanchette and Bernardo Broitman found that the number of young ochre sea stars at Santa Cruz Island rapidly increased. As they grew, the sea stars caused dramatic changes in the ecological community. Armies of the fi ve-armed predators ate so many California mussels that the mussel beds on rocky shores receded. Recently, however, the population of ochre sea stars has plummeted again, apparently due to a new outbreak of wasting disease following unusually warm periods in the Santa Barbara Channel. Blanchette and Broitman are studying ecological effects of the decline.

Sunlight Shapes Shoreline EcologyPrevious research by PISCO scientists uncovered puzzling ecological differences among sites along the Oregon coast. Some sites display high abundance and biomass of macrophytes (seaweeds and seagrasses) but low abundance of phytoplankton. Other sites host scant macrophytes but experience large blooms of phytoplankton. Experiments showed that biological interactions, such as grazing by herbivores, are not the whole explanation. Former PISCO/OSU postdoctoral fellow Karina Nielsen investigated another possible cause. By performing long-term measurements of underwater light conditions and macrophyte responses, Nielsen found that light conditions can limit the growth at some sites. Phytoplankton and other particles fl oating in the water block sunlight and shade macrophytes. PISCO scientists and Nielsen are col-laborating to further investigate the linkages among coastal oceanography, macrophyte growth, and differences in marine communities.

Karina Nielsen is now an assistant professor at Sonoma State University.

These graphs show the inverse relationship between phytoplankton abundance, measured as chlorophyll a concentration, and the biomass of macrophytes (seaweeds and seagrasses) in Oregon’s coastal waters. Cape Perpetua had high chlorophyll levels and low biomass of marine macrophytes, while the other sites had low chlorophyll and high macrophyte biomass.

Sea stars eat mussels at Santa Cruz Island.Photo: Carol Blanchette

Inverse Relationship between Phytoplankton and Macrophytes

Cape Perpetua has high levels of chlorophyll and few macrophytes (seaweeds and seagrasses). The phytoplankton in the water apparently inhibit macrophyte growth by blocking sunlight. At other sites along the Oregon coast, chlorophyll levels are low and macrophytes abundant. Photo: Karina Nielsen

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interdisciplinaryresearchtraining&

ISCO has expanded its course offerings to include a wide range of unique, interdisciplinary training for undergraduate, graduate, and postdoctoral students. The courses enable students to conduct high-quality, innovative research that supports science-based management.

• Biomechanics, Ecological Physiology, and Genetics. Offered by PISCO for several years, this month-long, six-days-per-week course is taught by PISCO scientists Mark Denny, Steve Palumbi, and George Somero. Students gain the conceptual background and skills to study environmental stresses in the ocean, physiological and molecular responses, and genetic variability.

• Physical Oceanography and Marine Ecosystems. PISCO scientists Margaret McManus, Jack Barth, and Libe Washburn teach this new, three-week, six-days-per-week PISCO course. Lectures, fieldwork, and computer laboratory sessions explore the critical role of oceanography in the ecology of coastal waters.

• The Science-Policy Interface for Marine Conservation. PISCO scientists Jane Lubchenco and Steve Gaines collaborate with experts in marine policy to teach this new two-week, intensive course. Students learn to analyze policy, synthesize scientific information relevant to policy, and share findings with policy makers.

PTraining a New Generation of Marine Scientists


interdisciplinary training & research

PISCO/UCSC student Rachel Barnett-Johnson.Photo: Abby Nickels

PISCO/OSU student Roly Russell. Photo: Francis Chan

Former PISCO/UCSB student Julie Kellner.Photo: Peter Kellner

Tracking Salmon to Their SourcePISCO/UCSC doctoral student Rachel Barnett-Johnson produced a thesis that pioneers links between geology and ecology to improve fi sheries manage-ment. With several collaborators, she developed geochemical techniques using strontium isotope ratios in fi sh otoliths (see PISCO Coastal Connections, Volume 3) to identify the birthplaces of Chinook salmon caught along the California coast. She found that these natural population markers can be used to identify the natal river or hatchery with 95 percent accuracy. The otoliths also function as “fl ight recorders” of fi shes’ movements among different habi-tats. Barnett-Johnson’s research promises insights into salmon migration and survival that will be critical for conservation.

Student Interdisciplinary Research

Changes in Biodiversity Affect Ecosystem FunctionHow might extinctions, invasive species, and shifts in species’ geographic ranges affect the health of ecosystems? PISCO/OSU doctoral student Roly Russell is working to provide some answers by studying seaweeds on rocky shores. Russell has found that carbon fi xation rates of biological communities are affected not just by the types of seaweeds present but also by the total number of species. The rates change because the photosynthetic behaviors of individual seaweeds are affected by the number of other seaweed species present. Russell’s research indicates that changes in biodiversity could funda-mentally alter ecosystem processes such as nutrient cycling.

Implications of “Fishing the Line” at Marine ReservesAt many fully protected marine reserves, fi shermen concentrate just outside the reserve boundaries. This practice of “fi shing the line” takes advantage of the movement, or spillover, of fi shes from protected areas into surrounding waters. As a PISCO/UCSB doctoral student, Julie Kellner examined the ecologi-cal and fi sheries management implications of fi shing the line. She found that, because this fi shing strategy is successful, it can strongly affect the spatial pat-terns of fi sh density, yield, and catch per unit effort (CPUE) inside and outside marine reserves. Therefore, consideration of this common approach to fi shing should be factored into the design of marine reserves.

Julie Kellner is now a Knauss Marine Policy Fellow with the NOAA Biogeogra-phy Program in Silver Spring, Maryland.

Opposite page photos, left to right: Sarah Ann Thompson,Luke Miller, Gretchen Hofmann

15

PISCO Coastal Connections • Volume 4sharing scienceTH

Eith several partners, PISCO co-sponsored the National Fisheries Conservation Center (NFCC) consensus conference on “Integrating Marine Reserve Science and Fisheries Management” held June 7–9, 2004, in Long Beach, California. This meeting of policy makers,

managers, scientists, and fishers explored potential applications of no-take marine reserves in fisheries management. An expert panel, including PISCO scientists Steve Palumbi and Steve Gaines, shared their knowledge about biological oceanography, marine ecology, fish biology, population dynamics, stock assessment, fishery management, fishery economics, and marine environmental law. A consensus statement from the conference, written by a review panel selected by the NFCC, provides some general conclusions, including the following key points.

Marine reserves:

• tend to increase the abundance and age ranges of fished species within their boundaries,

• protect habitats that are vulnerable to human disruption,

• are understood well enough to be incorporated into regional ecosystem-based management, and

• should be integrated with existing and emerging management measures for commercial and recreational fisheries.

The full text of the consensus is at www.nfcc-fisheries.org/consensus.

WConsensus on Marine Reserves

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and Fisheries Management


sharing the science

PISCO has played a key role in developing protocols and implementing the program to monitor the effectiveness of marine protected areas, including no-take marine reserves, around the Channel Islands. Research groups associated with the monitoring program are coordinated by the Cooperative Research and Assessment of Nearshore Ecosystems (CRANE), a statewide program sponsored by the California Department of Fish and Game (DFG). In 2004, CRANE organized and partially funded the MPA monitoring in the Channel Islands. With support from DFG and the Channel Islands National Marine Sanctuary, scientists from PISCO, Channel Islands National Park, and Milton Love’s research group at the University of California, Santa Barbara, have begun monitoring 25 protected and unprotected sites in the Sanctuary (see map). Fishermen, scientists, and the public provided input on focal species and the location of monitoring sites. Some sites previously had been monitored for years, which enables a better understanding of how the area’s ecology is affected by the new marine reserves and other protected areas. The monitoring program focuses on nine fish and thirteen invertebrates with a wide variety of life history characteristics, ecological roles, and histories of exploitation. PISCO scientists provide extensive training about target species and survey techniques to ensure that divers produce accurate, unbiased data. Monitoring will reveal how well marine reserves and other protected areas work, enabling federal and state agencies to adapt resource management accordingly.

Scientific Symposia SharePISCO Research

PISCO co-organized two major symposia at national scientific conferences in 2004. PISCO scientists Bruce Menge and Sergio Navarrete convened “Geographical Ecol-ogy: Variation in and Control of Species Interaction Intensity over Regional and Global Scales” for the annual meeting of the Ecological Society of America (see www.esa.org/program/symposia4.htm). At the American Association for the Advance-ment of Science (AAAS) annual meeting, PISCO/OSU scientist Jane Lubchenco and Andrew Rosenberg of the University of New Hampshire organized “Oceans Renaissance: Harnessing Nature’s Resil-ience through Ecosystem-Based Manage-ment.” Several speakers—including four members of the U.S. Commission on Ocean Policy and the Pew Oceans Com-mission—presented political and scientific perspectives on how to implement eco-system-based management of U.S. ocean waters. The symposia attracted interdisci-plinary audiences of scientists, policymak-ers, resource managers, representatives of non-governmental organizations, and informed stakeholders.

sharing the science

Kelp bass (Paralabrax clathratus). Photo: Laura Francis

Opposite page photos: Ralph Clevenger (left),Laura Francis (right)

Steve Palumbi (right) interviews Charles Birkeland, a lead-ing expert on corals. Photo: Dan Griffin

Monitoring the Effectiveness ofMarine Reserves and Other Protected Areas

Videos for Short Attention Spans

To share important findings with the public in an engaging way, PISCO scientist Steve Palumbi and Garthwait & Griffin Films are producing three-minute films that use a “reality science” format of field and laboratory research to cover selected issues in marine ecology and conservation. For more information, go to www.piscoweb.org/films.

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Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO)

For more information:Web site: www.piscoweb.orgE-mail: [email protected]

PISCOOregon State UniversityDepartment of Zoology3029 Cordley HallCorvallis, OR 97331

PISCOUniversity of California, Santa CruzLong Marine Laboratory100 Shaffer RoadSanta Cruz, CA 95060

PISCOUniversity of California, Santa BarbaraMarine Science InstituteSanta Barbara, CA 93106-6150

PISCOStanford UniversityHopkins Marine StationOceanview BoulevardPacifi c Grove, CA 93950

Photos, top to bottom and left to right: Laura Francis, Jane Lubchenco, Michael Webster, Sean Hoobler, Laura Francis, Sean Hoobler, Jane Lubchenco, Dave Lohse, Ralph Clevenger, Roly Russell, Sean Hoobler, Sean Hoobler

Paper stock contains 50% recycled content, 15% post-consumer content. Printed with linseed oil-based inks.

the partnership for interdisciplinary studies of coastal oceans · 2017-06-01 · ocean warming may...

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