This paper was written as part of the 2006 Alaska Oceans Sciences Bowl high school competition. The conclusions in this report are solely those of the student authors.

Monitoring Unalaska's Subsistence Species for Ecosystem-wide, Long-term Changes (MUSSEL Changes)

Authors

Monica Southworth
Eric Southworth
Mika Machalek
Aline Nguyen
Doanh Tran

Team Unalaska Ocean Raiders

Unalaska City School
PO Box 570
Unalaska, Alaska 99685

Abstract

With our region's climate constantly changing over time, it can be difficult to detect the effects these changes have on an ecosystem. Living in a small community that relies so heavily on the ocean's resources makes it crucial to understand what these changes are and how they may affect our resources in the future. Though the open ocean fisheries of the Bering Sea are considered to be the most important Alaskan ecosystem economically, it is the coastline of the Bering Sea that is most susceptible to change. The intertidal areas along the coast play pivotal roles in many fisheries as nurseries for juvenile salmon, halibut, cod and others. Many of Alaska's coastal communities depend a great deal on the foods that have culturally and historically, been collected in these areas. In addition to the nutritional, economic, and cultural importance of subsistence foods, many locals have observed that the presence/absence of these organisms seems to be tied to changes in climate.

In order to observe long-term changes in a productive intertidal area, our team has established several ways to monitor selected subsistence organisms to determine the effects of change on the coastal ecosystem. By creating programs to observe these important animals, the data can be used to determine trends over time, encourage environmental stewardship, and help resource managers or scientists in their decisions-making.

Introduction

In the last five years, the Bering Sea ecosystem has been witness to major die-offs of seabirds, population declines of some marine mammal species, and severely reduced returns of salmon to the Alaskan coast. Phytoplankton populations are changing from bloom-forming diatoms to slow growing, energy-deficient flagellates (http://www.pbs.org/harriman/explog/lectures/alexander.html). Jellyfish populations are booming and juvenile crab species are down (Purcell 2005). Commercially fished species such as king and Tanner crab, Pacific cod, Pacific halibut, and walleye pollock are fluctuating spatially and temporally, causing researchers, fisheries managers, and fishermen to ask the question "What is going on?" The variability in all of the components that make up the Bering Sea make this question a hard one to answer.

Changes in the atmosphere, ocean, and populations of marine species are occurring in the Bering Sea on interannual, decadal, and longer time scales. Systematic effects can be linked to the El Niño-Southern Oscillation (ENSO) on a 2 to 7 year scale. Changes due to the Pacific Decadal Oscillation (PDO) can be seen on a decadal to multi-decadal time scale (Mantua et al. 1997). The time series of both the ENSO and PDO indices are markers for significant changes known as "regime shifts" (Trenberth and Hurrell 1995). The physical mechanisms that drive "regime shifts" are tied to lunar/tidal changes, variations in solar radiation and changes in regional circulation. These changes, which are influenced by natural processes and human interactions, greatly influence the extent of sea ice, transport or nutrients, water column temperature and turbulence. Variation in these phenomena influences all of the biota through food-web dynamics and by directly affecting the biological rate and behavior of populations. Biological and physical characteristics such as temperature, mixing, currents, and timing can influence the hatching time, growth, and survival of marine organisms. Changes in biological interactions are also caused by the impacts of human intervention, such as commercial fishing, pollution and oil spills.

Ecosystem approach

When considering the future of the Bering Sea, decision makers will require a long-term commitment to a well-focused observing system. Recently, the focus of monitoring the environment has changed from an "organismal approach" to understand these changes to an "ecosystem approach."

The "ecosystem approach" to monitoring lies in the protection of the marine environment, the sustainable use of its natural resources, and the conservation of its biodiversity. All of these processes, along with human beings in the equation, create the mosaic in what we currently call the ecosystem. The development and application of the ecosystem approach focuses on the critical ecological processes, the ecosystem interactions and the chemical, physical and biological environment. The ecosystem approach is comprehensive. It's based on all of the biological resources within an area and it considers the economic health of the communities located within. The ecosystem approach is considered to be fundamental to achieving sustainable use and protection of the marine environment.

Alaska's resources

Alaska's oceans and coastal areas are unlike any other in the country in terms of their size, productivity, environmental quality, and management. The Bering Sea is the most productive area of the northern high latitude seas that serve as home to 450 species of fish and invertebrates, 50 species of birds and 25 species of marine mammals (Johnson 2003). Its waters border the Aleutian Island chain, comprised of 200 islands spanning a thousand miles from the Alaska mainland to Russia. The Aleutian Islands, most of which are part of Alaska, stretch out 2200 km (1200 nautical miles) west of the tip of the Alaska Peninsula.

Presently, the U.S. Bering Sea fishery contributes over half of the nation's fishery production, with a total commercial catch average annual value of approximately $2 billion. A prime example of this would be the biomass of the walleye pollock stock which is near 10 million metric tons. Bristol Bay supports the world's largest sockeye salmon fishery, and the snow crab fishery is currently the largest crustacean (by weight) fishery in the United States. The Bering Sea red king crab fishery began in 1966 with a net catch of just under one million pounds. Currently, the net catch is expected to be around 18.3 million pounds. The western Aleutians are home to one of the top fishing ports in the nation, Unalaska/Dutch Harbor, for ex-vessel value and pounds landed. In 2004, Unalaska ranked number one in volume of fish delivered in the nation with 849,135,924 pounds landed with an approximate value of $176 million (Kelty personal communication).

The Aleutian Islands and Bering Sea are home to several environmentally sensitive ecosystems and species including the endangered Steller sea lions, cold water coral gardens, and the endangered right whales. The Bering Sea is also suffering from a decrease in fishery productivity. Human interactions in the form of marine transportation, oil spills, marine mammal gear entanglements, and overfishing have frequent and important impacts on Aleutian waters. In addition, the Bering Sea supports 80% of the U.S. seabird population comprising 36 million birds of 35 species. Furthermore, many unique and endemic species such as red-legged kittiwakes and whiskered auklets are found in the Bering Sea.

The Unangan people of the Aleutians, also called 'Aleuts,' are distinctive among the world's people for their remarkably successful maritime adaptation to this cold archipelago. Residents of 12 communities throughout the islands interact daily with these resources for their cultural and subsistence uses, recreation, and as a means of economic survival. The residents of the Aleutians live in the small, geographically isolated (i.e. none are accessible by road, and are not road connected themselves) communities of Unalaska, Sand Point, King Cove, False Pass, Nelson Lagoon, Akutan, Cold Bay, Atka, Nikolski and Port Moller. The majority of the 12,000 residents are Alaska Natives that make at least part of their living by commercial fishing or working in a variety of service and/or professional positions.

Alaska's people are intimately connected to its oceans and coastal areas. The intertidal habitats of coastal Alaska are among the most diverse and productive of any ecosystem in Alaska. Despite their ecological significance, these habitats are being increasingly impacted by human activities. About 8,000 Aleuts live in villages along the Aleutian Bering Sea coastline, half of them in the main settlement of Unalaska. Alaska Natives continue a cultural dependence on the harvest of wild food that has lasted for thousands of years. Annual subsistence harvest levels by both Native and non-Native residents vary across the state from about 20 lbs per person in the urban areas of Alaska to a high of over 600 lbs per person in Bristol Bay (Hamrick and Smith 2003). Many of Alaska's remote coastal communities survive on a mixed and mutually dependent subsistence/cash economy. Observations made by local hunters and fishermen about the nearshore marine systems are highly valuable although vastly neglected in science-driven monitoring systems. The frequent users who become intimately connected with the sea are the ones who are more likely to observe unusual events that may be related to large-scale environmental changes.

Subsistence fishing, hunting and collecting are important aspects of the economy and cultural heritage of residents of the Aleutians. Estimated annual harvest of subsistence food in the region is 7,510,584 pounds valued at approximately $98 million dollars (Hamrick and Smith 2003). Although the importance of the sea and its resources to Alaska's subsistence users is established and widely recognized, the impact of changing environments may ultimately affect Alaska's coastline most of all. Awareness by coastal Alaskan communities of these phenomena and how they influence their subsistence habitats and food webs is vital for the ecological and sociological conservation of the region.

Case of need

According to the recent State of Alaska comments and recommendations to the U.S. Commission on Ocean Policy preliminary report, the National Ocean Council (NOC) should adopt the principle of ecosystem-based management and assist federal agencies in moving toward an ecosystem-based management approach (Recommendation 4–3). Present monitoring for existing resource management programs is woefully underfunded. The State of Alaska participates in the Environmental Protection Agency Environmental Monitoring and Assessment program that has only recently funded work in Alaska to survey the condition of Alaska's ocean and coastal habitat, water quality, sediment quality, benthic and fish resources.

Alaska's resource management have been somewhat successful due to a commitment to collaborate with federal and local management programs, nongovernmental interests, applied sciences, and environmental monitoring. However; small towns, such as Unalaska, are often left not knowing the implications of research and feel only the limiting effects of management.

In recent years, due to importance of commercial fisheries and fisheries related support, many coastal Alaskan towns have thrived. In several Bering Sea communities, the only reason the town exists is because of fishing. The communities receive money from the fish taxed and individual businesses receive money from purchases the boats make due to repairs and supplies. Clearly the importance of commercial fishing to coastal Alaska can be seen, but the importance of noncommercial, subsistence fishing, hunting and collecting is greatly underestimated.

Due to unknown changes, locally and globally, our ecosystem is changing and it is important for communities like Unalaska to understand the long-term impacts of these changes on resources that have come to define their culture.

Our project

Creating and adopting an "ecosystem approach" to monitoring Alaska's coastline would be a tremendous task requiring millions of dollars and years of effort. Currently, there is no standard mechanism to monitor change along the coastline of Alaska, much less to observe ecosystems dynamics of subsistence foods. In place of reinventing the wheel, we have decided to pilot the implementation of a proven monitoring program in Unalaska in the Spring of 2006. The Long-term Monitoring Program and Experimental Training of Students (LiMPETS) program, based in Southern California, is an intertidal monitoring program aimed at providing long-term data that can be used to follow changes in intertidal ecosystems, and will also introduce people of all ages to the rich biota of the intertidal, eventually building up a group of informed, concerned citizens who will watch over this habitat in the future. This program is relatively new and has proven to be very successful along the Pacific coast. LiMPETS is currently being performed in: Olympic Coast, WA (6 high schools), Gulf of the Farallones, CA (27 high schools), Monterey Bay, CA (9 high schools), and Channel Islands, CA (15 high schools).

The objective of our project is to establish a coastal monitoring program based on the LiMPETS protocols that will be used to observe long-term changes in Alaska's productive intertidal areas. The resource that we will monitor will be locally harvested marine invertebrate subsistence organisms that are important to the people of Unalaska historically, nutritionally, and culturally. We will focus on three organisms that: 1) are known to have the highest harvest levels, 2) are known to be indicators of change and 3) individually serve in different ecological niches in the intertidal ecosystem.

Organisms of Interest

We have chosen the green sea urchin, the blue mussel, and the black Katy chiton as focus species for our monitoring efforts. The blue mussel is a dominant space occupier, a filter feeder, and a food resource for many intertidal organisms. The black Katy chiton is an intertidal grazer, found in large populations, and maintains a relatively localized home-range. The green sea urchin is a grazer/scavenger that can dominate intertidal and subtidal areas foraging on everything available.

These organisms were selected because of their importance to Unalaskans as subsistence foods and as important players in the intertidal ecosystem. Based upon the Subsistence Food Use in Unalaska and Nikolski report by the Aleutian Pribilof Islands Association in 2003 and the recent subsistence foods survey performed for the Selendang Ayu Oil Spill Subsistence Workgroup, these three organisms were found to be the most predominantly harvested intertidal organisms. Additionally, these three organisms are generally accepted as important indicators to a changing environment.

Mussels

The blue mussel, or Mytilus trossulus, is a marine mollusk that lives in mid- to low-intertidal areas. Mussels live upon shores with high exposure both for protection and survival. On intertidal rocks, mussels tend to live in clusters and are a predominant space occupier often found dominating rock surfaces. Mussels are found from Baja California to arctic Alaska. They feed by filtering plankton out of the passing water. Sea stars, shore birds, crabs, various types of snails, and even humans are the main predators to the mussel species. Having the ability to close their valves enables mussels to tolerate physical, chemical and biotic factors that are involved with exposure to the atmosphere during low tide.

A benefit that mussels have upon the marine 'community' is that they can act as an indicator organism. Mussels have the ability to process large amounts of water. Since the amount of organic matter in seawater is low, having mussels filter seawater is beneficial. On an average, mussels have the ability to filter 7.5 liters of sea water/hour. Hydrocarbons that contaminate seawater often end up in mussels, which in turn may be harmful to humans.

Chitons

The black Katy chiton, or Katharina tunicata, is a marine mollusk that has eight protective plates and usually grow to be 6-12 centimeters long. Common to rocky shores that exhibit heavy wave action, these organisms hide in crevices or under rocks. They are generally a dark color, primarily black, and only a small "diamond-shaped" portion of their back is visible under water. These organisms can be found from Kamchatka, Russia, through the Aleutian Islands, Alaska, to southern California. They usually live in the middle to lower intertidal zones, where they wouldn't be exposed to the outside air when the tide goes down. These miniature creatures are motile grazers that diet usually on hydroids, bryozoans, algae, kelp, and sea lettuce. Sometimes they eat sponges, tiny barnacles, and spirorbid polychaetes. Although these organisms feed on plants such as these, they are victims of the food chain. Predators of chitons include sea urchins, leather stars, black oystercatchers, gulls, and even humans.

Many problems for chitons can occur because of where they live. Intertidal zones can be affected by industrial activities, such as oil and gas development, mining, timber harvest and seafood processing. Coastal damages are often caused by beachcombers, sewage discharge, harvesters of intertidal species, and over visitation. Global warming could also affect the chitons and the ecosystem they live in. People around the west coast are noting that numbers of cold-water species in intertidal communities are diminishing, and they believe it's because of warmer temperatures.

Chitons are important subsistence foods for people living in the ranges where it lives in the Bering Sea and Pacific Ocean. Alaska offers rocky shores and cold temperatures that allow chitons to thrive. Many native-Alaskans eat these organisms as subsistence foods and this contributes to the diminishing numbers of them in the past years. In many places including Bristol Bay, Ivanof Bay, Perryville, False Pass, and Chignik Lake, the number of households harvesting Chitons ranged from 57.1% to 100% based upon a survey given in these places (Hamrick and Smith 2003). All households were harvesting chitons for subsistence purposes. Because of this, the effects of subsistence harvest, trampling, and over-visitation on localized populations and community structure needs to be studied.

Urchins

The green sea urchin, or Strongylocentrotus droebachiensis, is an echinoderm often found on rocky shores from the mid-intertidal zone to waters half a mile deep. They are characteristically green, covered in short crowded spines. Sea urchins can be found all along the Pacific coast of North America from Alaska to southern California. These organisms feed on plant and animal matter including kelp, decaying matter, dead fish, sponges and mussels. Organisms that feed on sea urchins include crabs, sea stars, snails, sea otters, birds fish and people.

Urchins play a predominant role in the intertidal ecosystem as grazers and scavengers. Urchins will often amass in great numbers feeding on different types of algae. An increase in localized populations of urchins can cause "urchin barrens", areas completely grazed of all algae. Many intertidal and subtidal species, including many commercially important species, use kelp growths as protection and nurseries for early growth stages. Urchins, like all echinoderms are able to adapt to a changing environment. They can migrate long distances in search of food and can absorb their own tissues in times of famine. Urchin gonads are an important lipid and protein resource for rural Alaskans.

Methods/Management Plan

This pilot project will monitor our selected species, but also the abundance and distribution of other intertidal biota to determine changes in population dynamics and general health of the ecosystem. By creating this program, long-term data sets will be available to fisheries managers and research scientists, concerned citizens, and city officials. This program will also increase understanding and appreciation of intertidal habitats through direct involvement of middle and high school students and teachers, adult volunteers, and local tribal members.

Monitoring for this project will establish baseline data that can be used to detect trends or changes in ecosystem dynamics over time that will be useful to resource managers and scientists for decision making purposes. By establishing a set protocol, long-term sampling and data collection procedures will allow for replication over time.

In this endeavor, we also hope to establish a sense of environmental stewardship. This program is meant to be done by local Unalaskans for Unalaska. Though our goal is long-term monitoring to determine fluctuations in populations of species that act as indicators of change, we hope this information will instill in locals a feeling of pride and understanding in the intertidal areas being monitored.

As is the case with many Aleutian villages, Unalaska is exposed to violet storm acitivity for most of the year. The geology and bathemetry of Unalaska Island allow for a rocky coastline with very few sandy areas. As this is the case, our monitoring efforts will be limited to rocky intertidal areas only.

Our monitoring program will be developed to follow changes in biotic assemblages over time. Though we are focusing on three important organisms, we must also understand what is happening around those organisms. We will attempt to characterize sites by species easy to recognize and important to the community such as: major space occupiers (aggregating sea anemones, mussels, barnacles), grazers (turban snails, limpets, chitons), predators (sea anemones, sea stars, oyster catchers), or scavengers (urchins, sea stars). Sampling protocols will assume that abundance and distribution may vary with site and time and that common, easily recognized species represent the assemblage of the whole.

For our project, monitoring will be performed in rocky-intertidal areas employing three different sampling regimes. Total Counts will determine the abundance of conspicuous and important species over time and space. Vertical Transects will determine the abundance and distribution of predominant mega flora and fauna from the high to the low intertidal. Permanent Quadrats will determine the species composition change over time.

Total Counts will deal with total counts of large, conspicuous, important species in one or more defined areas. This project will determine if dominant species like mussels, chitons or urchins are increase or decreasing over time. Changes in abundance of these dominants may affect the local food web and ecosystem dynamics. Teams of 2-3 people systematically count every individual they see (estimates of true abundance). Five to ten teams will count the selected species in the same defined area, the average of their efforts will provide a reasonable estimate usable over time. Potential species include: seastars, limpets, urchins, mussels, chitons, bull kelp, or others as determined by initial surveys. Initial surveys will be used to determine the species present and conspicuous. Total Counts would be good for middle school curriculum with teacher and adult volunteer chaperones (Figure 1).

Vertical Transects will give the distribution and abundance of intertidal organisms along a vertical profile of the beach. This project will monitor if selected species (mussels, urchins and chitons) are moving up or down the vertical profile. This project may give insight into sea level changes, introduction of invasive species, or changing food web dynamics (competition or predation).

Transect tapes will be stretched from the high intertidal to low intertidal with ¼ m2 quadrats placed at a determined distance along the transect tape. Abundance of selected species will be counted so that changes can be noted over time. Transects will be randomly determined and GPS established so that the same transects and quadrats can be revisited annually. Permanent stainless steel stakes placed at the top and bottom of each of the transects. Vertical Transects would be good for middle school or high school curriculum with teacher and adult volunteer chaperones (Figure 2).

Permanent Quadrats will count selected species in randomly placed quadrats. This project will monitor changes in the abundance of selected species over time in a permanent area. This project may show the influence of competitive dominants or space occupiers in the presence of changing environmental conditions.

Using large relatively flat and uniform intertidal areas, rectangular plots will be made 15 to 30 meters on a side. Selected species will be counted in 10 to 20 randomly placed ¼ m2 quadrats. Once a quadrat has been placed, its four corners will be marked with marine epoxy to ensure accuracy in quadrat placement for future visits. GPS position and digital photographs will be taken along with species data. Permanent Quadrats would be good for high school curriculum with teacher and adult volunteer chaperones (Figure 3).

General considerations for monitoring

Monitoring will be based on efforts between the Unalaska NOSB team, the high school, middle school, and local adult volunteers. The three levels of monitoring will be coordinated with school teachers as part of their Spring 2006 curriculum. Adult volunteers will be solicited through local media and word of mouth. The protocols and project intentions were presented to the entire Unalaska City School District staff and faculty in November 2005. Response to participate and volunteer has been enormous. The number of sites for each of the projects will be determined based upon local participation.

The different methodologies for the three different monitoring efforts are primed to answer explicit questions about changes in the local intertidal ecosystem.

The Total Counts project will answer the following:

  1. Are there significant changes in the populations of dominant intertidal organisms at selected sites?
  2. Are populations changing over short-term and long-term periods?
  3. Are there any correlations between organism presence/absence?

The Vertical Transects project will answer the following:

  1. Are selected organisms moving up/ down the intertidal?
  2. Are aggregations of organisms influenced by sea-level changes?
  3. Are revisited transects homogeneous temporally?

The Permanent Quadrats project will answer the following:

  1. Is diversity maintained short-term/ long-term?
  2. Are dominant organisms consistently represented?
  3. Are human induced disturbances present?

Timeline

Results/Synthesis

To sustain a healthy and biologically diverse marine ecosystem, it is important to understand how its productivity is influenced by natural changes. Our understanding of these changes along with human-caused impacts will help us to determine the future of our ecosystem. We will be monitoring both the short-term and long-term changes in all of the proposed projects. Short-term observations will offer our community variations in the distribution and diversity of intertidal organisms on an annual basis. Long-term series of this data collection will allow us a larger picture of how changes in the ecosystem may be taking place and affecting our observed resources. Long-term observations will also take into account inconsistencies in sampling that may occur.

Problems limiting long-term coastal observations, especially in remote areas such as much of the Alaska coast, are the high costs that are involved with bringing out trained personnel to conduct these studies. In nearshore investigations, especially intertidal work, the involvement of volunteers and local communities can make a significant contribution. Implementing an ecosystem approach to monitoring Unalaska's intertidal areas will offer valuable information to locals, researchers and fisheries managers. This information will track important changes in our local intertidal areas that play a predominant role in the survival of subsistence organisms, commercially important species, and general heath of the ecosystem.

Oceanographic variables such as sea surface height, air/water temperature and rates of exposure will play important roles in the survivability of the selected organisms. The motility of urchins and chitons will prove an interesting contrast to stationary mussels. These variables will likely indirectly affect our organisms as both the predators and prey are susceptible to environmental changes. Our monitoring efforts will also take into account other variables such as marine debris and invasive species, both of which are top priorities/ recommendations in the recent Ocean Commission Report.

Our project goals are to establish a protocol for monitoring Unalaska's intertidal ecosystem over a long period of time and to encourage environmental stewardship for local kids and adults. This project is a test-pilot and subject to change as needed. The important thing for monitoring is that once a protocol has been established it is followed year to year, so that measurements are both accurate and repeatable.

To have the community adopt this program we have begun to solicit for volunteers, we are establishing a website so that locals can observe the monitoring efforts first hand, and we have used teachers in the planning so that they may implement programming into their curricula.

The end result of our efforts will be the establishment of a protocol that envisions the "ecosystem approach" to observe long-term changes in our intertidal areas while encouraging environmental education and outreach that will allow local people to appreciate the ecosystem in which they live. The potential for this program to be run in other communities is a very plausible outcome, especially considering the program is run through school systems. Perhaps with these monitoring efforts, coastal Alaskans will develop a better understanding of ecosystem dynamics that may in turn encourage conservation efforts in these productive areas.

Figures

grids for total counts project

Figure 1. Grid for Total Counts project.


quadrat layout for vertical transects project

Figure 2. Quadrat layout for Vertical Transects project.


example placements for permanent quadrats project

Figure 3. Examples of placements for Permanent Quadrats project.


References