Research & Monitoring

 

Biological staff at Jamestown S’Klallam Tribe assist several organizations with research projects that will answer questions about the marine environment—which will in turn lead to good resource management decisions.

 

Geoduck Growth and Recruitment:

Subtidal geoducks (Panopea abrupta) in the Puget Sound, Strait of Juan de Fuca, and Hood Canal regions of western Washington consist of subpopulations of sedentary adults connected through the dispersal of larvae. Although subpopulations are not clearly discreet, they are grouped into “tracts” of clams for the purpose of population assessment and harvest management. Geoduck tracts range in size from 1.6 to 485 hectares, or approximately four to 1,197 acres. There are presently no studies that describe the larval connectivity between these tracts and regions. Without scientific evidence for an alternative approach, management of the geoduck resource in Washington State assumes a single and homogeneous population. Researchers at the University of Washington (UW) are studying reproductive and growth patterns of geoducks throughout the Puget Sound basin by examining growth increments in geoduck shells and by studying and comparing the genetic structures of geoducks. State and Tribal fishery biologists will use the information gathered during this study to guide management of subtidal geoduck populations.

 

During the summer of 2005 Jamestown commercial geoduck divers and biological staff collected geoducks from the seafloor near Protection Island in the Strait of Juan de Fuca. These samples, combined with others collected by State and Tribal agencies, are being incorporated into the UW geoduck recruitment study. The objectives of the study are 1) To identify spatial and temporal patterns of geoduck recruitment, growth, natural mortality, and post harvest recovery; and 2) To characterize the habitat-specific processes responsible for these spatial and temporal patterns.

 

Effects of Commercial Geoduck Harvest on Benthic Infaunal Communities:

Tribal and State fisheries for geoduck clams (Panopea abrupta) are economically important in Washington. However, a quantitative understanding of the ecosystem-level effects of disturbances associated with geoduck harvests does not exist. Clams are taken by liquefaction of seafloor sediments with diver-operated hand-held water jets. Researchers at the UW have been studying the effects of subtidal geoduck harvest operations to fill this data gap. Biological staff from the Jamestown S'Klallam Tribe have assisted researchers during the field components of this project.

The primary objectives of the study are: 1) To determine direct effects of disturbances associated with actual commercial geoduck harvests on benthic infaunal communities; and 2) To estimate patterns and duration of succession and ecosystem recovery that follow harvest-associated disturbances. Data will be applied to the development of disturbance-recovery models for ecosystem-level effects of geoduck harvest.

 

Climate Reconstruction Using Growth Increments in Geoduck Shells:

Little is known about how the marine environment in the North Pacific has changed over time, but we know from recent experience that climate profoundly affects productivity and ecology in the ocean. The oldest ocean temperature records for our region extend only to the 1920s and proxy records have primarily been derived from tree-rings. Tree rings provide good records of change on land, but are not ideal tools for inferring marine conditions. Geoducks are much better candidates to provide annual, and possibly seasonally, resolved records of marine environmental change for our region. Variations in growth rates and geochemical properties of growth increments in geoduck shells reflect variations in conditions that occur during growth (temperature, food, ageing).

 

This project is being led by scientists from the University of Frankfurt and Washington Department of Fish and Wildlife (WDFW) Point Whitney Laboratory. Major goals of the project are to construct master chronologies of geoducks in the Northeast Pacific. Variations in growth rates will be used to infer environmental and climate conditions during the most recent period of the Holocene. Geochemical data also provide an independent measure of environmental conditions. Measures of d18O and d13C ratios in the growth increments will shed light on the relationship between environmental variables and growth rates. Biological staff from the Jamestown S'Klallam Tribe have assisted researchers by placing and monitoring seafloor water temperature gauges, collecting water samples at the seafloor, and providing geoduck shells from the primary study area which is located near Protection Island in the Strait of Juan de Fuca.

 

Spot Shrimp Fecundity:

The spot shrimp, Pandalus platyceros, is a commercially important shrimp that resides in deep waters along the coast of Washington State. Pandalid shrimp are protandric hermaphrodites—they begin life as males and later change sex to become females when they reach a certain size. A female spot shrimp can carry as many as 3,600 fertilized eggs in a mass or “skein” under her abdomen or head. Commercial, recreational, and subsistence spot shrimp fisheries are conducted when 97% of randomly sampled female spot shrimp have completed their seasonal reproductive activities by releasing their eggs into the water column. This is determined by conducting fecundity tests. Biological staff at the Jamestown S'Klallam Tribe routinely conduct tests in the Strait of Juan de Fuca. Data collected include the size and sex of all shrimp, the presence of eggs on females, weights of egg masses, and numbers of eggs contained in each skein.

 

A primary objective of this work is to examine fecundity (reproductive potential) by comparing ovigery ratios (numbers of egg-bearing females relative to the sampled population) and to determine the mean number of eggs produced by females relative to overall body weight. The latter test is an essential index for a stock recruitment model being designed by WDFW.

 

Sea Urchin Stock Assessment:

Sea urchins are members of a large group of marine invertebrates called Echinoderms, which means ‘spiny skin.’ As the name implies, sea urchins have an outer surface armed with long spines that protrude through a round, calcareous shell, or test. These spines are used for locomotion, protection, and trapping food particles such as drift algae. Between the spines are tube feet and arms with small pinchers called ‘pedicellarine’ that can grasp food and rocky surfaces, and further aid in locomotion. These arms and spines are connected through a closed network of canals that compose the water-vascular system, which is similar to the circulatory system in vertebrates, but which also provide the animal with a means of transportation and respiration. The mouth opening is located on the underside of the animal, and wastes are eliminated through an opening at the top of the test.

 

Urchins are generally composed of both male and female sexes, and it is the skeins of gonads contained within the tests of the animals that support commercial dive fisheries. The red urchin, Strongylocetrotous fransciscanus, is a commercially valuable species found subtidally in the Strait of Juan de Fuca. The State fishery was initiated in the early 1970’s, and harvests peaked in 1988. Since 1990 the State fishery has been managed under a limited-entry system. A large portion of the Strait of Juan de Fuca has been closed to red urchin harvest because State and Tribal managers believe populations of these animals are depressed in the region.

 

Jamestown staff research divers have been assisting research divers from WDFW with surveys of red sea urchins in the Strait of Juan de Fuca to gather information about the abundance and distribution of this important and interesting marine invertebrate. Survey results are being used to guide management of the species.

 

Cadmium Content of Intertidal Oysters:

The trace mineral, Cadmium, is an element that occurs naturally in the crust of the earth. It is found in varying concentrations in coal and oil deposits and in ores such as iron, sulfide, and lead and copper that contain zinc. Small amounts of Cadmium are leached from soils during rain events and find their way to marine waters of the Pacific Northwest through overland runoff. Other sources of Cadmium include combustion of fossil fuels, phosphate fertilisers, PVC products, photocells, automobile radiators, some textile dyes, electronic components, batteries, and ceramic glazes. Cadmium is released into the air or water during the production, combustion, or disposal of these products. While air and water (and smoking) are sources of Cadmium, food can be a significant source of Cadmium exposure. Trace levels of Cadmium are present in plants, fish, and shellfish.

 

Consumption of foods that contain unacceptable levels of Cadmium can have negative effects on human health. To protect human health, governments establish limits on Cadmium levels in foods such as shellfish. The Pacific Shellfish Institute (PSI) has been studying Cadmium concentrations in molluscan shellfish in Pacific Northwest marine waters to understand the spatial and temporal distribution of Cadmium in commercially important shellfish species such as Pacific oysters. Staff from the Jamestown S'Klallam Tribe are assisting PSI by collecting samples from Dungeness and Sequim Bays for the study. Data will be used to evaluate the risks to human health, the economic risks to industry, and possible methods to minimize residues of this mineral in shellfish products marketed to consumers.

 

Paralytic Shellfish Toxin Study:

Paralytic Shellfish Poisoning (PSP) is a condition caused by consuming shellfish that contain high levels of a neurotoxin, or saxitoxin, produced by the dinoflagellates that are the primary food source of many marine bivalves. Symptoms of PSP include tingling of the lips and face, numbness, paralysis, and even death if the amount the saxitoxin ingested is sufficiently high. The dinoflagellate responsible for production of the PSP toxin in Pacific Northwest waters is Alexandrium catenella. Saxitoxins are produced naturally by A. catenella, but environmental conditions play a large roll in the life cycles and levels of toxicity of these phytoplankton cells. For instance, the greatest amount of toxin will be produced when water temperatures, sunlight, and nutrients in the water are high, which will induce the rapid growth of cells that is often referred to as an algal “bloom.” As the bloom grows, essential nutrients and carbon dioxide are consumed and environmental conditions become degraded. Eventually cell populations level off, and further degradation of water quality can lead to a population crash. The leveling of the population can trigger the development of resting cysts, which settle to the seafloor where they can lie dormant for months or years, waiting for the conditions to become ideal for another bloom.

 

Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels contained within the algal cells of interest. In the case of paralytic shellfish toxins (PSTs), particulate toxin levels and the effects of dietary consumption of toxic cells by planktivores have been well documented. Little effort has been invested into quantifying the levels of dissolved PSTs that may be released into seawater from toxic cells during blooms. In order to fully evaluate the risks of harmful algal bloom toxins in the marine food web, it is necessary to understand all potential routes of exposure. Biological staff from Jamestown S'Klallam Tribe have been collaborating with researchers from NOAA to collect and process water samples from Sequim Bay to shed light on this subject. Results confirm that A. catenella cells do release toxins into seawater, that this release is highly variable, and that the dissolved route of exposure may pose a risk to larval planktonic organisms that overlap spatially and temporally with PSP blooms.