Northern abalone (Haliotis kamtschatkana) recovery strategy: chapter 1
1. Background
Date of Assessment: May 2000
Common Name (population): northern abalone
Scientific Name: Haliotis kamtschatkana
COSEWIC Status: threatened
Reason for designation: A patchily distributed marine mollusc found along the west coast. Highly prized for harvesting, it continues to decline since complete closure of the fishery in 1990, probably as a result of continued high levels of poaching. There is evidence that the decline and fragmentation of the population are impairing the reproductive ability of the species even though there persists a reservoir of reproductive adults.
Canadian Occurrence: Pacific Ocean
COSEWIC Status History: Designated threatened in April 1999. Status re-examined and confirmed in May 2000. Last assessment based on existing status report.
Abalone are a marine mollusk related to snails and whelks. The northern abalone, Haliotis kamtschatkana (Jonas 1845) is one of approximately 65 species of abalone (Haliotis spp.) found world-wide (Geiger and Poppe, 2000). H. kamtschatkana is called ‘pinto’ abalone in the United States, in keeping with the tradition of naming abalone according to their colour. In B.C., the term ‘northern’ is used as the species is the world’s northernmost abalone (Sloan and Breen 1988).
The ear-shaped shell of northern abalone is relatively small, thin, elongate-oval and low, with three to six open holes, and sculpture of irregular lumps superimposed over the spiral structure. The colour is mottled reddish or greenish with areas of white and blue (McLean 1966). The top of the shell is usually camouflaged with algae. The mother-of-pearl on the inside of the shell is less colourful than many other species (the New Zealand paua, H. iris, is the species most commonly seen in jewelry) and lacks a muscle scar. The muscular foot is fringed with tentacles. Two prominent tentacles mark the anterior end of the abalone. The top spiral is carried posterior.
Northern abalone are found off the west coast of North America in shallow subtidal waters along exposed and semi-exposed rocky coastlines from Yakutat, Alaska (O’Clair and O’Clair 1998) to Turtle Bay, Baja California (McLean 1966). In Canada, northern abalone occur only on the Pacific coast in patchy distribution on hard substrate in the intertidal and shallow subtidal. Most of the adult abalone occur in near shore, exposed or semi-exposed coastal waters at <10 m depth.
Canada – B.C.
The northern abalone population has been assessed in B.C. since 1978 through surveys of index sites using a standard survey design (Breen and Adkins 1979). Many of the surveys between 1978-90, and much of the commercial fishery, were conducted in areas along the south-east Haida Gwaii / Queen Charlotte Islands (QCI) and the central coast of B.C. (Winther et al. 1995; Harbo 1997; Campbell et al. 1998). Most surveys were conducted in areas with significant commercial harvests, where northern abalone were most abundant (Sloan and Breen 1988). Although there were a few surveys of southern B.C. (Quayle 1971; Breen et al. 1978; Adkins 1996; Wallace 1999), they did not afford the extended coverage provided by the northern surveys.
Surveys at index sites in south east QCI and the central coast of B.C. have provided general time-series trends indicating that the abundance of northern abalone declined more than 75% between the period of 1977-84 and remained low and or continued to decrease through 2002 (Winther et al. 1995; Thomas and Campbell 1996; Campbell et al. 1998, 2000a; Atkins et al. 2006; Lessard et al. 2006). The mean total northern abalone density at comparable index sites changed from 2.4 to 0.27 abalone per m2 for the central coast, during 1979-2001, and from 2.2 to 0.34 abalone per m2 for QCI during 1977-2002. The similarity in northern abalone density between new random sites and index sites indicated that the mean densities from all index sites were reasonably representative of adult northern abalone sampled in areas of the central coast of B.C. in 1997 and south east QCI in 1998 (Campbell et al. 1998, 2000a). Other surveys using different sampling designs also confirmed the low densities of northern abalone found by the index surveys in the same areas (Lessard et al. 2002; J. Lessard, Fisheries and Oceans Canada, Nanaimo, BC, V9T 6N7, pers. comm.)
Examination of surveyed index sites in both QCI and the central coast indicated a general decline in the number of sites with at least one northern abalone per m2 between 1978 and 2002 (Campbell 2000b, Atkins et al. 2006; Lessard et al. 2007). The proportion of index sites with large adult abalone (≥ 100 mm shell length (SL)) generally decreased from 89% and 77% to 27% and 25% for the central coast and QCI, respectively. The decrease in density and decline in the number of sites with northern abalone suggested serial depletion of large abalone.
Surveys and observations in southern B.C. have indicated even lower densities of northern abalone (J. Lessard, pers. comm.). New index site surveys were initiated on the West Coast of Vancouver Island in 2003 (WCVI) and in Queen Charlotte and Johnstone Straits in 2004. Limited surveys were conducted in Georgia Basin in 2005. The mean total density estimate was 0.09 abalone/m2 for WCVI from all sites sampled, but 0.21 abalone per m2 in Quatsino Sound where more sheltered abalone habitat was present (Atkins et al. 2004). The mean total density estimates were 0.06 abalone per m2 in Queen Charlotte Strait and 0.02 abalone per m2 in Johnstone Strait (Davies et al. 2006). Wallace (1999) reported relatively high population abundance of northern abalone in an area close to William Head Penitentiary, near Victoria, where the presence of penitentiary guards may have discouraged poachers from nearshore access. However, during the more recent surveys at William Head in 2005, only three individuals were found at two (11%) of the 19 sites surveyed, and all were large (>100mm SL). The most likely reason is simply that the large abalone found during previous surveys died and recruitment was low (J. Lessard, pers. comm.). The mean density for all sites surveyed in Georgia Basin in 2005 was 0.0098 abalone per m2, which was significantly lower than the densities estimated in 1982 and (0.73 abalone per m2) and 1985 (1.15 abalone per m2) in the same area. The lack of immature individuals and low adult density suggest poor potential for future recruitment in this area.
Breen (1986) and Sloan and Breen (1988) suggested that abalone populations probably fluctuated even in the absence of commercial fishing. Exploratory surveys conducted in south eastern QCI during 1955 by Quayle (1962) suggested that northern abalone were less abundant in 1955 than in both 1914 (Thompson 1914) and in the late 1970s (Sloan and Breen 1988). The extirpation of sea otters from B.C. by early 1900s had an effect on a number of invertebrate populations, including northern abalone. With the re-introduction and recent expansion of the sea otter population, restoration of the northern abalone population to the levels seen in the late 1970s is unlikely.
Global – U.S.A.
The IUCN Species Survival Commission has listed the global status of H. kamtschatkana as endangered based on an observed population size reduction of >50%. Although the observed declines in B.C. and Washington showed a population size reduction of >80%, the assessment judged that “the historical elimination of sea otters led to abnormally large pre-exploitation level [of abalone]” and accordingly reduced the classification from critically endangered. The assessment considers significant populations of northern abalone to be absent south of San Juan, Orcas and Lopez Islands in Washington State (IUCN 2005).
By comparison to B.C., the average density of northern abalone in Washington in 2006 at the San Juan Island index sites was 0.032 abalone per m2 and ranged from 0.000 to 0.082 abalone per m2; two sites out of ten had no abalone (Don Rothaus, Washington Department of Fish and Wildlife, Mill Creek, WA 98012-1296, pers. comm.). Pinto (i.e., northern) abalone were designated as a ‘State Candidate Species’ in Washington in 1998 and were listed as a ‘Species of Concern’ by NOAA Fisheries in 2004 for protection under the federal Endangered Species Act.
There are no estimates of population density from Alaska since the commercial fishery closed in 1996 (IUCN 2005).
Northern abalone are normally found on firm substrates, such as rocks, boulders, or bedrock, and in areas of moderate to high sea water exchange, such as in exposed or semi-exposed coastlines. Most of the adult northern abalone occur in near shore, exposed or semi-exposed coastal waters at <10 m depth (Breen and Sloan, 1988).
Currently, there is ample habitat available for the northern abalone population on the coast of B.C. Although the abalone population has declined, there has been no known significant reduction in available habitat. Therefore, habitat loss is not a major concern in the recovery of northern abalone at this time in comparison with the identified threats.
Northern abalone growth can vary considerably between areas depending on the extent of exposure to wave action and availability and quality of food. Growth of adults tends to be stunted in highly exposed outer coastal areas where food may be limited because of strong wave action and water currents (referred as ‘surf abalone’). Feeding opportunities may be reduced because abalone would be less able to catch and hold onto drift algae. When “surf” abalone were transplanted to calmer, kelp abundant habitats, growth rates were higher than for abalone in high-energy areas (Emmett and Jamieson 1988). Abalone growth was more rapid in moderately exposed areas with giant kelp, Macrocystis integrifolia, or bull kelp, Nereocystis luetkeana,kelp forests than at highly exposed areas with Pterygophora californica kelp forests (Sloan and Breen 1988).
Adult northern abalone aggregate in warm shallow water areas to broadcast their gametes simultaneously (Breen and Adkins 1980). Spawning off B.C. generally occurs between April and July. Large female northern abalone (> 100 mm SL) contribute substantially more to population fecundity than small mature abalone (Campbell et al. 1992; Campbell et al. 2003). Cues that cause mass spawning in Haliotis spp. can include environmental factors such as temperature changes (Sloan and Breen 1988), and minor storms and typhoons (Sasaki and Shepherd 1995). Studies on Haliotis spp. (Clavier 1992; McShane 1995a,b; Shepherd and Partington 1995; Babcock and Keesing 1999) and sea urchins (Levitan et al. 1992) have emphasized reduced fertilization success can be caused by dilution of gametes through reduced adult spawner densities (Levitan and Sewell 1998). Since fertilization success depends on the aggregation density of abalone, exploitation rates and high natural mortality on abalone aggregations are likely important in influencing egg production (Campbell 1997).
Within 48 hours after fertilization, the planktonic trochophore larvae emerge from their egg membranes. The planktonic phase of northern abalone is short and temperature dependent (12 days at 14 degrees Celsius, 13 days at 17.5 degrees Celsius)(Standley 1987). Larvae settle on crustose algae (Sloan and Breen 1988). Small juvenile (<10 mm SL) northern abalone are hard to find. Juvenile northern abalone (10-70 mm SL) are found under and on exposed areas of rocks, whereas the majority of adults (≥ 70 mm SL) are found on exposed rock surfaces. More juvenile abalone emerge on to exposed rock surfaces at night than in the day. Densities of juvenile abalone (≤ 30 mm SL) surveyed at study sites in the Pacific Rim National Park Reserve were significantly higher (by a factor of 15.74) at night than in the day (H. Holmes, Parks Canada Agency, Pacific Rim National Park Reserve, Ucluelet, BC VOR 3A0, pers. comm.). As the juveniles develop to maturity, their diet changes from benthic diatoms and micro-algae by moving to shallower, more exposed areas to feed on drift macro-algae. The general habitat areas of the adults and their juvenile offspring could be within close proximity of each other. Studies have suggested that larval dispersal in some Haliotis spp. may occur in small geographic areas, on a scale of hundreds of meters to several kilometres (Tegner and Butler 1985a; Prince et al. 1987; McShane 1992, 1995a,b; McShane et al. 1988).
1.4.2 Ecological role
Within the near shore, exposed or semi-exposed coastal waters, northern abalone play the role of herbivore and are prey of many species. Recovery of northern abalone may be related to the abundance and health of kelp forests in certain areas. Northern abalone compete with other species (e.g., red sea urchins, Strongylocentrotus franciscanus) for food and space. Northern abalone are prey for sea otter, Enhydra lutris; river otter, Lutra canadensis; mink, Mustela vison; crab, Cancer species; sea stars, Pycnopodia helianthoides; octopus, Octopus dofleini; wolf eel, Anarrhichthys ocellatus cabezon, Scorpaenichthys marmoratus; and other sculpin fish species, Cottidae spp. The role of sea otters in shaping the nearshore kelp forest ecosystem likely has a significant impact on the structure of the northern abalone population where the two species co-exist. Studies have shown that abalone, in areas where sea otters are present, are restricted to crevices and other cryptic habitats where they are inaccessible or hidden from sea otters (Watson 2000).
1.4.3 Limiting factors
The northern abalone is vulnerable to harvest because this species has a patchy distribution, a short larval period, is slow growing, relatively long-lived, and has low or sporadic recruitment. Also, mature individuals, which tend to accumulate in shallow water, are easily accessible to harvesters.
The appropriate size and distribution of the northern abalone population required to provide effective reproduction and subsequent sufficient recruitment are unknown. Current knowledge of abalone species, in general, suggests there needs to be sufficient densities within patches of large mature abalone close enough together to successfully spawn and produce viable offspring (Babcock and Keesing 1999).
Recruitment is defined as the number of juveniles growing and surviving to the adult population. Generally, high densities of adult northern abalone are required to ensure sufficient recruitment. Shepherd and Partington (1995), using a Ricker stock recruitment curve, suggested that there was a critical stock density threshold (0.15 per m2) for the H. laevigata in Waterloo Bay, South Australia, below which the risk of recruitment failure was high. Later studies by Shepherd and Rodda (S. Shepherd, SARDI Aquatic Sciences, Henley Beach, South Australia, pers. comm.) have shown higher thresholds at around 0.3 per m2. Shepherd and Brown (1993) found that a “minimum viable population” of more than 800 individuals of H. laevigata was required at West Island, Australia; anything less caused recruitment failure. Shepherd and Baker (1998) suggested that recruitment to an abalone fishery could be relatively lower and more variable in small abalone populations than in larger populations. In this case, small populations would need to have more egg production to prevent depletion. These studies supported the influence of the Allee effect or depensation (Allee et al. 1949) in which low abalone densities and few aggregations reduced reproductive success due to low fertilization of gametes.
Recent modelsimulations suggested that mortality would have to decrease in order for northern abalone populations to increase (Lessard et al. 2006).
Long harvested by coastal First Nations, abalone (Haliotis spp.) meat was consumed as food and the shells or pieces of shell of northern abalone or red abalone (H. rufescens) traded from California were used in B.C. as fishing lures, in jewelry and as an inlay for carvings (Stewart 1977, Sloan 2003). Abalone buttons on a ceremonial blanket were a sign of wealth to the Tsimshian (Reece 2000). Harvest was generally restricted to the lowest tides, although some, such as the Haida, also used a three-pronged spear to access abalone in subtidal areas, 2 m below the lowest tide (Jones 2000). B.C.’s coastal First Nations express continued concern that the northern abalone population is threatened, which results in food, social and ceremonial fisheries being closed[1]. Interest in food, social and ceremonial fisheries for abalone has provided an incentive for northern abalone rebuilding programs in some areas. Some of these programs go beyond the objectives of the recovery strategy, but nonetheless support northern abalone recovery.
In addition to the concerns of First Nations, the closures of B.C.’s commercial and recreational abalone fisheries represented significant economic and recreational loss to participants, associated industries and coastal communities. While small recreational and commercial fisheries for northern abalone occurred in B.C. as early as 1900, a commercial dive fishery directed on northern abalone began in earnest in 1972. Developing through the 1970s, B.C.’s commercial fishery peaked in 1977 with landings of 481 t. The majority of harvest occurred in the north and central coast of B.C. and in the Queen Charlotte Islands (Adkins 2000; Campbell 2000b). The value of the commercial fishery peaked at $1.86M (landed value) in 1978 (Sloan and Breen 1988). Northern abalone were also regarded as a gourmet food and recreational divers were known to have had a keen interest in northern abalone harvest. Conservation concerns led to the complete closure of all northern abalone fisheries in B.C. in 1990, including recreational, commercial and First Nations’ food, social and ceremonial fisheries.
There is no other abalone species occurring within Canada’s Pacific Coast with sufficient abundance to directly replace the northern abalone fisheries. Recreational and commercial dive fisheries and First Nations’ food, social and ceremonial fisheries continue for other invertebrate species (the value of commercial invertebrate fisheries in B.C. is significant, currently estimated at $122.1M) (2005 British Columbia Seafood Industry Year in Review).
There is currently no commercial harvest of northern abalone. There has never been a commercial fishery for northern abalone in Washington State, and Alaska's commercial fishery was closed in 1996. The recreational fishery in Washington also closed in 1994, but there is currently an Alaskan sport/subsistence fishery. Other species of abalone (e.g., red abalone, H. rufescens) from aquaculture and commercial fisheries in other jurisdictions (including Australia, Mexico, China, Chile, and the U.S.) are still available in B.C.
Pilot projects were initiated in 2000 under the abalone rebuilding strategy (Dovetail 1999) to develop aquaculture techniques for northern abalone in B.C. The Bamfield Huu-ay-aht Community Abalone Project (BHCAP) continues to provide support to the abalone recovery strategy (including population rebuilding by out-planting hatchery-raised northern abalone to the wild) and also has the goal of providing economic opportunity in the community. The BHCAP’s operations are authorized under section 73 of SARA. The first sales of cultured northern abalone were made by BHCAP in 2006.
Recreational diving and tourism associations have expressed an interest in maintaining healthy aquatic environments, including healthy and abundant invertebrate communities, which generally support abalone recovery efforts. The general public also has an interest in addressing species at risk and maintaining a healthy environment.
1.6.1 Threat classification
| 1. Illegal harvest | Threat Information | |||
|---|---|---|---|---|
| Threat Category | Consumptive Use | Extent | Widespread | |
| Local | Range-wide | |||
| General Threat | Harvesting | Occurrence | Historic and current | |
| Frequency | Continuous/recurrent | |||
| Specific Threat | Illegal Harvesting | Causal Certainty | High | |
| Severity | High | |||
| Stress | Reduced population size | Level of Concern | High | |
| 2. Low recruitment | Threat Information | |||
| Threat Category | Changes in Ecological Dynamics or Natural Processes | Extent | Widespread | |
| Local | Range-wide | |||
| General Threat | Low (or no) recruitment | Occurrence | Historic and current | |
| Frequency | Unknown | |||
| Specific Threat | Insufficient spawner densities and natural causes | Causal Certainty | High | Medium |
| Severity | High | High | ||
| Stress | Reduced population size | Level of Concern | High | |
| 3. Works or developments on,in and under water | Threat Information | |||
| Threat Category | Habitat Loss or Degradation | Extent | Localized | |
| Local | Range-wide | |||
| General Threat | Works or developments on, in and under water | Occurrence | Anticipated | |
| Frequency | Recurrent | |||
| Specific Threat | Alteration of habitat characteristics (e.g., siltation), or loss of habitat (e.g., obstruction, burying) | Causal Certainty | High to unknown | |
| Severity | High | Low | ||
| Stress | Reduced population size | Level of Concern | Low | |
| 4. Sea otter predation | Threat Information | |||
| Threat Category | Changes in Ecological Dynamics or Natural Processes | Extent | Overlapping portion of range | |
| Local | Range-wide | |||
| General Threat | Sea otter predation | Occurrence | Current and Imminent | Anticipated |
| Frequency | Continuous or Recurrent | Unknown | ||
| Specific Threat | Altered predator-prey dynamics (predation) | Causal Certainty | Medium | Unknown |
| Severity | High | Unknown | ||
| Stress | Increased mortality and unknown effects on population dynamics | Level of Concern | Medium | |
1.6.2 Description of threats
Continued illegal harvest and low recruitment levels have had predominant and widespread impacts and are considered to be the most significant threats to northern abalone recovery.
Illegal Harvest
Mature northern abalone, which tend to accumulate in shallow water, are easily accessible to harvesters. The market value of abalone, and the difficulty in enforcing the fisheries closures in a large, mostly uninhabited coastal area, has encouraged illegal harvesting. Illegal harvesting not only depletes the already depressed northern abalone population, but also reduces their reproductive potential by removing large mature abalone and leaving the remaining mates too far apart to successfully spawn. Samples from northern abalone illegally harvested during 1995-98 suggested that harvesters indiscriminately removed mostly large mature abalone (Campbell 2000b). Recent mortality rates estimated by Lessard et al. (2006) indicated that the mortality rate (all sources) for northern abalone were too high to be sustainable.
In 2006, three separate abalone poaching events culminated in February when Fisheries Officers seized the largest single haul of illegally harvested northern abalone in Canada’s history; 1,120 kg or an estimated 11,000 animals were seized. Illegal harvesters have generally come from coastal communities, and the abalone have been destined for sale or personal consumption. Convictions for buying or selling northern abalone have been made in recent years against seafood wholesalers in Vancouver and a Chinese restaurateur in Victoria, B.C. The Courts have taken illegal harvesting seriously; heavy fines, forfeiture of vessels, vehicles and gear, and prohibitions on fishing are now standard sentences.
Without reductions in illegal harvest, protection of mature abalone, a continued closure of the fisheries, and other effective rehabilitation methods, northern abalone population abundance will remain low or continue to decline in many areas.
Low Recruitment
Low recruitment in an area, over a protracted period of several years, may contribute to further declines in the northern abalone population by not replenishing the reproductive adults that have died from natural causes or illegal harvest. Generally, high densities of adult northern abalone are required to ensure sufficient recruitment (refer to Section 1.4.1 Habitat and biological needs).
Low recruitment caused by unfavourable environmental and biotic factors usually can not be predicted nor controlled. Ensuring that there are sufficient adult northern abalone to reproduce each year will allow high recruitment to occur when environmental conditions are favourable.
Habitat Loss or Degradation
Works and developments on, in, and under the water (e.g., marinas, loading facilities, aquaculture farms) may have negative impacts on northern abalone habitat and numbers in localized areas, and will need to continue to be monitored and regulated in order to maintain habitat in which the northern abalone can be recovered and to prevent losses to important spawning aggregations. Protocols for authorizing and monitoring works and developments around abalone habitat have been developed (Lessard et al. 2006).
Sea Otter Predation
Historically, sea otters were common in coastal regions of the North Pacific. They were hunted to near extinction from the mid-1700s until protected in 1911, and were reintroduced to B.C. by the Federal and Provincial governments in a series of three translocations of 89 sea otters in 1969, 1970, and 1972 (Watson 2000). The sea otter population is also listed as threatened under SARA (2003). In areas off the west and north coasts of Vancouver Island and in the Goose Group on the central coast of B.C., where sea otters are now established, sea otters prey on northern abalone, reducing the density, size, and distribution of northern abalone compared to areas without sea otters (Breen et al. 1982; Watson 1993). While sea otters are clearly not responsible for the observed decline in the northern abalone population over the last few decades, as the range of sea otters expands, northern abalone may only be sustained at low levels.
Northern abalone and sea otters have co-existed in the past before the extirpation of sea otters. However, the levels at which they co-existed or whether populations may have fluctuated in the past is unknown. The majority of knowledge on the northern abalone population has been in the absence of sea otters.
Sea otter expansion may be a concern in areas where the abalone population is already depleted and may make meeting abalone recovery objectives, as currently defined from areas without sea otters, impossible. Provided sufficient densities of northern abalone remain to be able to reproduce successfully, sea otters may in the longer-term help northern abalone recover by increasing kelp and algae biomass and thereby increasing the food supply available to abalone. This interaction has been highlighted as a knowledge gap (refer to Section 1.8). Refinements to the abalone population and distribution objectives for areas with sea otters may be necessary with improved knowledge of species interactions.
Surveys of Key Index Sites (1978-present) have been conducted every 1-5 years to monitor population abundance and evaluate recovery. These broad scale surveys are considered representative by providing time-series trends of the northern abalone population.
Closures to Commercial Fishing (1971-1990). The Lower Johnstone Strait, Georgia Basin and Strait of Juan de Fuca were closed in 1971 to commercial fishing to provide for recreational fishing opportunities. In addition, there were a number of closures to the commercial fishery to provide for First Nations and recreational harvest (Farlinger, 1990).
Total Fisheries Closures December (1990-present). All B.C. fisheries, including commercial, recreational and First Nations’ food, social and ceremonial fisheries, were closed to abalone harvest in 1990. There are currently no commercial fisheries for northern abalone anywhere.
Threatened Status (1999) and Legal Listing (2003-present). Northern abalone were designated by COSEWIC as threatened in 1999 and legally listed under SARA in 2003 (with the Act’s proclamation). A re-assessment of northern abalone’s status by COSEWIC is in preparation and anticipated to be made in 2009.
Enforcement measures have been undertaken by regular patrols in support of the harvest prohibition and in response to reports of illegal activity. Covert operations and investigations target specific poaching operations. Penalties and court imposed fines have become significant in recent years.
An international Workshop on Rebuilding Abalone Populations in British Columbia (1999) was held in February 1999, and convened individuals from local communities, First Nations, international research institutes and government organizations to focus on developing solutions to rehabilitate northern abalone populations (approximate cost $100K). Thirteen peer-reviewed papers were presented (Campbell 2000a) and a Strategy for Rebuilding Abalone Populations in British Columbia was prepared by Dovetail Consulting Inc. The broad approaches and strategies of this Abalone Recovery Strategy were drawn from this workshop.
Pilot Projects in support of rebuilding the wild abalone population (2000-present). In 2000, Fisheries & Oceans Canada in co-operation with several First Nations, coastal communities, and the aquaculture industry, initiated several pilot projects in support of rebuilding wild abalone populations.
Rebuilding Sites: The Haida Fisheries Program and Kitasoo Fisheries Program have established long-term rebuilding sites to improve recruitment by aggregating reproductively mature adults. The Haida Fisheries Program and Pacific Urchin Harvesters Association initiated a joint research project in 2004 to study interactions between northern abalone and red sea urchins, a potential competitor of abalone. The Heiltsuk Abalone and Sea Otter Stewardship Project established rebuilding sites in 2004 and will include studies on the effects of sea otters on the abalone population. These activities are supported also by habitat and population assessment (surveys), community education and awareness and Abalone Coast Watch to protect the abalone population. Fisheries & Oceans Canada and Parks Canada Agency established research sites in 2002 in and around Pacific Rim National Park to investigate local habitat requirements for recruitment and to test the rebuilding technique of aggregating reproductively mature northern abalone. Current modeling and night surveys by Parks Canada Agency were used to predict and assess juvenile recruitment from the aggregation sites. Preliminary results indicate that aggregation increases localized recruitment. Aggregation studies are authorized under the Fisheries Act and section 73 of SARA.
Development of Culture Technology and out-planting: The Bamfield Huu-ay-aht Community Abalone Project was established in 2001 and made the first out-planting to the wild of hatchery-raised northern abalone in 2003. Since then, 2 million abalone larvae and 75,000 young juveniles have been out-planted to the wild. BHCAP made the first sales of cultured northern abalone in 2006. Hatchery-raised abalone are available to research studies (e.g., disease, feeding, effect of finfish farms, interactions with red urchins) that could not previously be conducted with wild abalone. The BHCAP’s activities are authorized under the Fisheries Act and section 73 of SARA.
An Abalone Recovery Team (2001) was formed in November 2001, with representatives from the federal departments of Fisheries and Oceans Canada and Parks Canada Agency, and the Provincial Ministries of Environment (formerly Water, Land and Air Protection) and Agriculture and Lands (formerly Agriculture, Food and Fisheries).
Eight Workshops (2002) for coastal B.C. communities (Bella Bella, Port McNeil, Powell River, Port Alberni, Victoria, Nanaimo, Prince Rupert, and Skidegate) were held in February 2002 as forums to receive input on the recovery strategy from all interested parties. Concurrently, the recovery strategy was reviewed by seven external reviewers representing academia, government, and non-government organizations from Canada, U.S.A., Australia and New Zealand.
A National Recovery Strategy for the Northern Abalone in Canada (2002) was adopted under the Accord for the Protection of Species at Risk in November, 2002. This was one of the first marine recovery strategies, and the first in the Pacific Region.
Index Sites in southern B.C. (2003-2004)have been established to monitor population abundance and evaluate recovery in Queen Charlotte and Johnstone Straits and the West Coast of Vancouver Island. Limited surveys were conducted also in Georgia Basin in 2005.
Scientific documents and publications produced to increase the knowledge base regarding northern abalone (see References and Additional Reading).
Anti-illegal harvest communications campaign consisted of multiple activities and the production of communications products by Fisheries & Oceans Canada and abalone stewardship projects to raise public awareness of the current status of northern abalone and the harms of continued illegal harvest. Materials produced include an abalone web site, news releases, education curriculums and presentations in local schools, translated articles in the Asian press, posters, stickers, tattoos, t-shirts, water bottles and community brochures, websites, ‘Observe-Record-Report’ reporting forms, newsletters, and workshops. Numerous newspaper stories, particularly in recent years, and have also supported the campaign.
Abalone Genetics Research (2001). The population structure of northern abalone has been determined in B.C. and a forensic DNA technique has been developed to identify confiscated abalone to species to support enforcement against illegal harvest.
Larval Dispersal, Patch Size and Recruitment
Currently very little is known about the relationship between northern abalone adult concentrations, breeding success and subsequent dispersal of larvae and settlement of juveniles. Juvenile northern abalone are cryptic (i.e., hiding in cracks and crevices and unobservable to survey) and difficult to survey effectively until they reach maturity. Low abundance and fragmentation of the population are considered to be impairing the potential reproductive success of northern abalone. The frequency and size of patches of northern abalone required to maintain sufficient recruitment for a healthy population requires further investigation. While a stock-recruitment model was recently developed for the first time for northern abalone (Lessard et al. 2006), a better measure for cryptic animals to assess recruitment is still required.
Species Interactions
A better understanding of the ecological interactions between northern abalone and abalone predators (e.g., sea otters) and competitors (e.g., sea urchins) is required. The sea otter, a significant predator of northern abalone, is expanding its range in B.C. following extirpation and re-introduction. Most of the studies on the northern abalone population have been in the absence of sea otters and abalone recovery objectives are based on life history parameters that have been determined without the influence of sea otters. Sea otters affect the size and density of northern abalone, and may also influence factors such as size at maturity and the portion of the population that remains cryptic. Sea otters will also affect the abundance and distribution of other abalone predators, including Dungeness and other crabs, and abalone competitors, particularly red sea urchins. Currently, the factors that facilitate co-existence of sea otters and northern abalone are unknown, and further research on these factors is needed. Recovery objectives in the presence of sea otters need to be determined. In some areas, increased predation from the expanding sea otter population on an already reduced and fragmented northern abalone population poses a concern for northern abalone recovery.
Rebuilding Techniques
Tagged abalone remain relatively close to their transplant site in the first year (B. DeFreitas, Haida Fishery Program, Massett, BC , pers. comm.; J. Lessard, pers. comm.), which is likely sufficient time to allow for spawning. A preliminary study by Parks Canada Agency and Fisheries & Oceans Canada indicates that aggregating reproductive adults may contribute significantly to local recruitment (Parks Canada Agency, in preparation). Out-planting juvenile abalone has had some limited success with other species in other jurisdictions (Seki and Taniguchi 2000; Shepherd et al. 2000; Tegner 2000). The recent work in B.C. indicates that shelter from predation and, possibly, selection of sites with lower abundances of predators are important considerations for out-planting, particularly for juvenile northern abalone <12mm SL (Griffiths 2006). Further evaluation of the rebuilding techniques for northern abalone in B.C. is required.
Diseases/Parasites
Abalone disease has severely impacted wild abalone stocks in California (e.g., foot withering syndrome), however it is unknown if the causative agent (a rickettsia-like organism that infects the epithelium of the digestive tract) or other parasites reported in California (e.g., kidney coccidia) occur in northern abalone in B.C. As random sampling of wild northern abalone in B.C. for a disease survey is not a feasible approach due to low population levels, abalone in culture are being sampled. Broodstock obtained from the wild population will harbour parasites enzootic to the area of collection and these organisms may become evident under culture conditions. Also, hatchery-raised abalone produced in culture will reflect the agents of disease occurring in the vicinity of the culture facility (given the current restrictions with transplanting abalone between different regions of the province, cultured abalone should not develop "exotic" diseases). As well, in the event cultured abalone are used in rebuilding (out-planting) experiments, these animals should have prior disease screening to ensure that only healthy abalone are introduced into the wild population.
Extent of Illegal Harvest
Known quantities of illegally harvested B.C. northern abalone have ranged from <45 to 4500 kg (Jubinville 2000). Prior to the closure of the commercial, recreational, and First Nations fisheries in 1990, and continuing afterwards, there has been illegal harvesting at unknown exploitation rates, and despite the closure, northern abalone has not shown signs of natural recovery. The density of large mature abalone (>100mm SL) has continued to decline at survey index sites, and is reported to be declining at other locations. Anecdotal information suggests that illegal harvesting occurs on a scale significant enough to cause a severe conservation risk to this species.
Clarification of Habitat Concerns
The extent to which works or developments on, in or under the water (e.g., finfish farms, floating camps) may pose a threat to northern abalone by direct and indirect impact(s) in localized areas is unknown. To date, only one study (Lessard et al. 2006) has specifically examined the indirect impact from finfish farms on northern abalone, using hatchery-raised abalone. Although the study had some difficulty due to poor survival overall, growth was decreased in proximity to the farm sites in comparison to the controls. A protocol for authorizing works and developments on, in and under the water where abalone are present (Lessard et al. (2006)), therefore, adopts a precautionary approach to the authorization of sites in abalone habitat. The protocol includes provisions for monitoring and collection of additional data.
Identification of critical habitat
Although abalone habitat (Section 1.4.1) is not considered to be limiting, there may be certain habitats where juvenile survival is better, or where the reproducing adults contribute to a larger portion of the total recruitment. Identification of this key habitat is included as part of the abalone research and rebuilding plans.
[1] In the event abalone populations are recovered to sufficient levels, priorities will be given to First Nations’ food, social, ceremonial fisheries pursuant to Section 35(1) of the Canadian Constitution.
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