State of the North Sound and Straits: Bottomfish, Salmon and Shellfish

Lauren Mulroy is a graduate of Huxley College and served as a RE Sources intern. Robyn du Pré served as the North Sound Baykeeper and coordinated water programs at RE Sources for eight years. She currently teaches field-based environmental studies for the Audubon Expedition Institute.

Part Three

Editor’s Note: This is the third of a multi-part series on the health of northern Puget Sound and Georgia Strait. It was first published under the title, “State of the North Sound and Straits,” by RE Sources and North Sound Baykeeper in October of 2002.

True to their name, bottomfish live mainly on or near the bottom of the Sound and Straits. The most-well known groups of bottomfish include rockfish, lingcod, Pacific hake and sole. Most bottomfish, especially lingcod and true cod, tend to be relatively long-lived and rather sedentary, often not straying far from their home territory. These traits, along with the fact that many species reach sexual maturity relatively late, make bottomfish species vulnerable to over-harvest and habitat destruction that may occur during drag-fishing and the construction of underwater structures such as pipelines.

Lingcod prefer rocky bottoms and reefs as their habitat. Because of their size and flavor, lingcod are considered a favorite among recreational fishermen. Currently, stocks of lingcod are considered very low, and the Washington State Department of Fish and Wildlife (WDFW) has listed lingcod populations in north Puget Sound as depressed.

Various rockfish species can be found in rocky bottom and reef environments ranging from the shallow saltwater near shore to depths of over 3,000 feet. These fish do not lay eggs, but give birth to live young and reproduce year after year. Recent losses of larger-sized fish from rockfish populations in North Puget Sound has resulted in a 75 percent decline in their spawning potential since the 1970s (Eisenhart, 2002).

Rockfish reach sexual maturity relatively late, ranging from four to 14 years, depending on the species. Losing the older females from the population results in a decrease in reproductive ability of the species as a whole that is greater than simply the number of fish taken. (Huhtala, 2002)

Like lingcod, stocks of rockfish are considered very low and have been listed as depressed by WDFW. A recent stock assessment indicates that the yelloweye rockfish population has declined over 80 percent from natural levels (WDFW). Some of these populations have declined so much, that today even a one-fish-per-day catch limit may be unsustainable.

Even so, these fish have been denied federal protection under the U.S. Endangered Species Act. The National Marine Fisheries Service (NMFS) claimed that Puget Sound populations are not distinct enough from relatives in other regions, however they did acknowledge the obvious changes occurring throughout the ecosystem leading to their sharp decline.

English sole stocks in Puget Sound and the Northwest Straits are also considered very low. Like other bottomfish, English sole feed in bottom sediment, and use nearshore habitats as nursery or breeding grounds.

Because of their close proximity to human uses, nearshore habitats are often the locations where environmental degradation is the greatest. Many contaminants issuing from runoff and industrial sources tend to settle out of the water column, accumulating in the sediments where bottom-feeding organisms such as English sole are then exposed to them.

Two recent studies have shown English sole from industrialized areas in Puget Sound take up and accumulate chemical contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenols (PCBs). (Johnson, 1998 & Collier 1997) These studies present evidence of increased incidence of liver lesions and cancers, altered immune function and increased susceptibility to infectious disease.

Harvest of bottomfish has averaged around 70,000 pounds per year from 1995 to 2000. This harvest level is at the lowest it’s been in 55 years, and today some bottomfish are estimated at only 5 percent their natural populations. These harvest levels are viewed by many as unsustainable, and WDFW is considering further restrictions. (WDFW)

“We’ve been harvesting groundfish faster than they can reproduce. Some very popular and valuable stocks, such as lingcod, are in poor condition in the ocean. Rebuilding them is going to take more sacrifices from fishers, processors and our coastal communities,” says Phil Anderson, Pacific Fishery Management Council member and special assistant for Intergovernmental Affairs to Jeff Koenings, director of the WDFW.

Over-harvesting of another species of bottomfish, Pacific hake, led the state to close commercial harvesting in 1987(WDFW). Stocks of two close relatives of hake, Pacific cod and walleye pollock, have also declined to the point of a ‘critical status’ rating.

Varying environmental conditions, such as changes in water temperature and marine mammal predation, may be contributing to the low stock numbers. Unsustainable harvest levels, however, have been the major factor in the decline of these bottomfish stocks.

Restrictions on harvest in order to help bottomfish species rebound have not yet led to successful recovery rates. This is probably because many of these species are slow growing and mature very late in their lives. Long-term restrictions on harvest of these bottomfish are necessary in order to give these slow-growing fish time to rebound.

Recognizing this issue and the relatively sedentary nature of these fish, many in the scientific and conservation communities are now exploring the efficacy of Marine Protected Areas (MPAs), or no-harvest zones, for species recovery. Research indicates that setting aside productive bottomfish habitat as protected serves an important role in species recovery.

As the populations inside MPA boundaries grow, juvenile fish leave the MPA to establish their own territories, positively affecting population abundance in surrounding areas. This phenomenon has caused some to refer to MPAs as “nurseries of the sea.”

Serious Trouble: Over-harvest has already almost completely depleted some rockfish stocks, while contaminated sediments contribute to the declining health of species such as English sole. Serious efforts must be made to bring regional populations of many bottomfish species back from the brink.

Five species of salmon are native to the waters of Puget Sound: sockeye, pink, chum, coho and chinook. In addition to playing a key role in both marine and freshwater ecosystems, salmon are an integral part of north coast Indian culture and support our economy by providing jobs and recreation for fishermen throughout Washington.

Fluctuations in yearly catches caused by a variety of factors, such as changing ocean conditions, complicate but do not mask the overall decline of salmon populations in the region. As the situation becomes more critical each year, salmon have become symbolic in representing the decline in the health of aquatic ecosystems in the Northwest.

Currently, the Puget Sound chinook has been listed as ‘threatened’ under the U.S. Endangered Species Act. In the late 1970s, nine of 25 Puget Sound chinook stocks were in poor condition.

Today, 22 of the 25 stocks fail to meet spawning goals. The chinook stocks from the Nooksack (north and south forks) are among the worst in the state. The Skagit River has also failed to meet spawning goals for several consecutive years. (WDFW, 1998)

Many factors have led to the salmon’s decline. Logging results in increased siltation of streams and loss of important overhanging streamside vegetation. Dams block salmon from migrating upstream or harm salmon as they travel downstream towards the ocean, while road construction often creates impassable culverts and impervious surfaces. Water diversion from streams for use in agriculture, power generation, or as drinking water, has also severely impacted salmon runs.

Competing demands among commercial, tribal and sport fisheries create pressures for an unsustainably high catch. As well, wild stocks of salmon face competition from the many salmon bred in hatcheries that compete for limited food and habitat in inland waters.

Wild stocks and hatchery salmon also intermingle on their return home to spawn, resulting in the further decline of wild salmon stocks, as they are caught in the same nets as hatchery salmon and compete for limited migration corridors and spawning habitats.

Loss of marine habitat is another threat to salmon in the region. Some species, such as chum, require eelgrass for forage and protection. Shoreline development can destroy eelgrass and other essential habitat by altering the natural beach and creating deep water close to shore. Pollution from urban runoff, industrial and municipal wastewater, pesticide runoff and household chemicals all degrade the water salmon rely on for spawning.

Serious Trouble: Many salmon stocks have already been listed as threatened. Habitat continues to be degraded and destroyed, while harvest rates are at unsustainable levels. Restoration efforts are promising, but only deal with small portions of the complex habitat needs of these anadromous fish.

A diverse population of shellfish, including crabs, oysters, clams and mussels, hold tremendous value in the area. Shellfish are an important economic resource, and occupy key ecological niches in marine and estuarine waters. Shellfish have long sustained native populations and helped to define local customs and cultures.

Dungeness crab can be found in kelp and eelgrass beds and on sandy or muddy substrates of the intertidal and shallow subtidal areas. This crab serves as both predator and prey in marine and estuarine waters and is food to many aquatic species such as salmon, halibut, octopus, shorebirds and waterfowl.

This tasty and abundant crab is very popular among commercial and recreational harvesters. In Puget Sound, harvest has increased steadily from more than two million pounds in 1992-93 to a record 7.7 million pounds in 1999-2000. This large increase in harvest can be attributed to a growing number of recreational crabbers, easy access to crabbing areas, and the decreasing availability of other harvestable shellfish. (PSWQAT, 2000)

Despite increased harvest and sediment contamination in many areas, Dungeness crab populations in the region appear to be thriving. However, harvest pressures are sure to continue especially while many other species are in decline.

Clams, mussels and oysters are also important resources in the Pacific Northwest. Puget Sound harvests make Washington state the largest producer of cultured clams and one of the top two producers of cultured mussels in the western United States. The oyster industry in the Sound is one of the two most significant sources of commercial oysters nationwide.

Unfortunately, this industry, along with the enjoyment of recreational shell fishers has been seriously impacted by fecal coliform contamination. Among the Puget Sound’s most contaminated sites for fecal coliform bacteria are Drayton Harbor, South Skagit Bay and Portage Bay, near the mouth of the Nooksack River.

Since 1980, almost one quarter of the area available for commercial harvesting has been downgraded in classification because of bacterial contamination. These classifications are based on an examination of potential pollution sources and measured levels of fecal coliform bacteria in marine waters. This bacterial indicator reflects the presence of human or animal waste, potentially carrying disease-causing bacteria and viruses.

In the year 2000, the entire embayment of Drayton Harbor was downgraded to “Prohibited to Harvest” due to poor water quality, and approximately 2,550 acres are currently closed to harvesting there. Portage Bay has been placed on the Department of Health’s “threatened area list” due to fecal coliform pollution. Approximately 150 acres are currently closed to harvesting in Portage Bay.

At Drayton Harbor, dairy and farm waste, sewage system leaks, contaminated urban stormwater and other non-point source pollution, as well as boat wastes and other activity in the vicinity of the Blaine Marina all contribute to fecal contamination. Major fecal contamination in Portage Bay can be attributed primarily to drainage from livestock operations along the Nooksack River. (Washington Department of Health—WDOH, 2002)

In South Skagit Bay, nine of 14 shellfish growing stations have exhibited increasing levels of fecal contamination, and in Dungeness Bay on the Strait of Juan de Fuca, 11 of 13 stations are getting worse. These downgrades are due primarily to agricultural practices and septic system issues.

Shellfish are filter feeders, filtering many times their weight in water. With this capacity come significant problems when pollutants, such as heavy metals and bacteria, are present. Industrial pollutants, farm runoff and septic system failures all pose a substantial threat to these shellfish populations.

Increased urbanization and agricultural practices have had a detrimental effect on shellfish beds. Contaminated runoff from farms, streets, home landscapes and parking lots, as well as discharges from sewer and septic systems, all threaten the health of shellfish beds in the area.

Outlook Good: Many shellfish-growing areas are contaminated beyond state health standards, and increasing incidences of red tide and excess nutrients also negatively impact shellfish beds. But, this contamination does not appear to affect the health of the shellfish themselves—only our ability to safely eat them.

However, in addition to making shellfish inedible to humans, fecal coliform contamination is an indicator of generally poor water quality. We’ll need to clean up our act, but shellfish can thrive and we will once again harvest them. §

Next Month—Part Four