Abalone

The Northern Abalone (Haliotis kamtschatkana) is found from Alaska to Baja California and is the only species occurring in British Columbia (BC).Most adult abalone occur in nearshore, exposed or semi-exposed coastal waters at <10 m depth. Abalone are aggregating synchronous broadcast spawners and fertilization success depends on the local density of adults and dilution of gametes.Surveys at index sites have provided a time series of abalone densities and size frequencies from the south-east Haida Gwaii and the central coast of BC (CC) every 3-5 years during 1978-2002.Abundance of northern abalone in these areas declined more than 75% between 1978 and 1989-90. DFO banned the harvest of northern abalone in December of 1990 due to concerns of low population numbers. Despite the harvest closure, numbers remained low and in 1999 Northern Abalone was listed as ‘threatened’ by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).As a result of the official listing, a National Recovery Strategy for the Northern Abalone was prepared.

The short-term measurable objective set out in the recovery strategy is: “[to] ensure that mean densities of large (≥100 mm shell length (SL)) Northern Abalone do not decline below 0.1/m2 at surveyed index sites in Haida Gwaii and North and Central Coast, and that the percentage of surveyed index sites without large (≥100 mm SL) northern abalone does not increase to greater than 60%”. In other words, the percentage of index sites with large abalone should not fall below 40%.

Densities of Northern Abalone have continued to decrease despite a total ban on harvest since 1990. There is no current evidence of population recovery in BC.Low recruitment levels and continued harvest despite the fisheries closure are considered to be the most significant threats to northern abalone recovery. Expansion of the sea otter population and near shore marine development may also contribute to the decline of abalone in B.C.

Species at Risk

Abalone Life Cycle

Photo: Abalone with seaweed growth. (Photo: James Pegg)Northern Abalone are found in shallow subtidal waters along exposed and semi-exposed rocky coastlines from Alaska, to Baja California. In B.C., abalone occur in patchy distribution on hard substrate in the intertidal and shallow subtidal zones.

Northern Abalone are considered mature at a size of 50-64 mm SL, depending on local habitat conditions. Large female Northern Abalone (e.g., >100 mm SL) are more fecund than small mature abalone.Spawning generally occurs between April and July.Abalone spawn synchronously, with groups of males and females gathering in shallow waters, broadcasting their gametes into the water column.Cues that initiate mass spawning in abalone can include environmental factors such as temperature changes and minor storms. Recent studies on abalone and sea urchins have documented reduced fertilization success caused by dilution of gametes due to reduced adult spawner densities. Since fertilization success depends on the aggregation density of abalone, exploitation rates and high natural mortality on abalone aggregations may be important in influencing juvenile recruitment.

Within 48 hours after fertilization, trochophore larvae emerge from the eggs. This planktonic phase of northern abalone is short and temperature dependent (10-14 days at 14-10°C).Recent studies have suggested that larval exchange in some abalone species may occur in small geographic areas (on a scale of hundreds of meters to several kilometres).

Photo: many abalone in a netVery little is known about the early juvenile stages (1-3 years) of Northern Abalone in BC and further study is required. Small juveniles (<10 mm SL) are hard to find, but are usually associated with crustose algae. 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. As juveniles develop to maturity, their diets change from benthic diatoms and micro-algae to drift macroalgae.

Northern Abalone growth can vary considerably between areas depending on the extent of exposure to wave action and availability and quality of food.

Estimates of the age at which Northern Abalone reach 100 mm SL range from 6 to 8 years in BC. 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. Feeding opportunities may be reduced because abalone are less able to catch and hold on to drift algae. Abalone growth is more rapid in moderately exposed areas with giant kelp, Macrocystis integrifolia, or bull kelp, Nereocystis luetkeana, forests than in highly exposed areas with walking kelp, Pterygophora californica, forests.

Major natural predators of Northern Abalone include sea otters, crabs, octopus, some fishes, and sea stars (especially Pycnopodia helianthoides).

Due to the slow growth rate, sporadic recruitment, and cryptic juvenile stage, the stock-recruitment relationship of northern abalone is unknown and may be difficult to determine.

Abalone Research

Photo: Exposed Gonad of an abalone (Haliotis kamtschatkana)The size and distribution of Northern Abalone populations required for effective reproduction and subsequent sufficient recruitment are unknown. Current knowledge of abalone, in general, suggests that there needs to be sufficient densities within patches of large mature abalone close enough together to successfully spawn and produce viable offspring. The immediate research goal is to determine an effective method to increase the density of mature northern abalone to self-sustaining levels. Prior to attempting full scale rebuilding, feasibility studies need to be conducted to determine the suitable rebuilding method(s) to address the problem of poor adult recruitment and to fill knowledge gaps on northern abalone biology and ecology (Abalone recovery team. 2002). A collaborative multifaceted study was initiated in 2002 in the Broken Group Islands, Barkley Sound. The project had two primary objectives: 1) to identify recovery areas critical to conserving Northern Abalone; and 2) to explore field methods that improve abalone reproduction and recruitment in pilot experimental research areas.

  1. Increase reproductive potential of mature abalone.
    Photo: Measuring abalone (Photo: Laurie Convey)Experiments include 1) testing the translocation of abalone from low growth areas to higher growth areas to increase reproductive potential, 2) and testing survey methods for estimating adult abundance and key habitat characteristics. In 2002 and 2003, 2000 abalone were tagged and transplanted from an exposed location to 3 experimental sites, and 2 control sites. Surveys have been conducted at each site once a year to determine possible changes in density, the resulting effect on recruitment, and estimation of abalone growth curves from tagged abalone recovery data. Initially, the sampling design used perpendicular transects to survey abalone density and size frequency. The transect design proved to be imprecise to detect small changes in abalone abundance and the design was changed in 2003 to a Plot Survey where the sampling frequency is increased over a small area. The Plot survey has been applied to all experimental sites in since June 2003.

    One of the goals of the translocation experiment was to determine if the transplanted abalone would stay within the recipient new habitat. All the abalone translocated, were tagged in order to monitor their movement and survival within, and possibly outside, each experimental site. The results of the tag recovery indicated that a significant portion of the translocated abalone stayed within their new habitat. The use of two tagging methods, also proved useful and lead to recommending that the ‘dangling’ tag be use in the future because of the ease to find these tagged abalone when compared to more traditional ½in disk tag. Furthermore, since each abalone was uniquely tagged, it was possible to also monitor natural growth over several years.
  2. Test survey methods for estimating juvenile abalone abundance.
    Photo: Taking DNA sample of abalone.(Photo: Laurie Convey)Northern Abalone grow slowly and it would take 5-7 years to determine if the aggregation experiment was effective if conventional survey methods were used. Furthermore, an understanding of recruitment processes is important in developing a recovery strategy for northern abalone. Little information is available on the early life stages of northern abalone. Small juvenile abalone, which represent the first 1-3 years of the benthic stage, are usually cryptic and hard to find. This makes standard survey techniques used to measure adult abalone abundance ineffective for studying juvenile abalone densities since searching inside deep crevices and underneath heavy boulders is difficult and time consuming. Therefore alternate methods of sampling juveniles are needed.

    Methods tested for feasibility as abundance indices for recruitment of early stages included, (i) settlement collectors, (ii) artificial habitats, (iii) venturi suction sampler, (iv) magnifying glass, (v) rock removal, (vi) searching cryptic quadrats, and (vi) night surveys.

  3. Continue or establish long term index site surveys.
    Index sites have been surveyed in south east QCI and along the central coast of BC since 1978. In 2003 new index sites were established along the NorthWest coast of Vancouver Island, and in 2004 new sites have been surveyed in Johnstone and Queen Charlotte Straits. Along with monitoring abalone density, the surveys are important for estimating algal food availability, distribution, and abundance of competitors (urchins).

Several programs are in place with local communities and First Nations groups to rebuild abalone stocks, and to raise awareness to help reduce poaching of northern abalone.

Abalone Publications

Illustration of an abaloneBelow are some selected publications by the Abalone program.

Citations may include abstracts (HTML) or the full document may be available for viewing as an Adobe Acrobat file (*.pdf).


Lessard, J., M. Atkins and A. Campbell. 2007. Resurvey of northern abalone, Haliotis kamtschatkana, populations along the central coast of British Columbia, April 2001. Can. Manuscr. Rep. Fish. Aquat. Sci.: 2791: 36p.

Atkins, M., J. Lessard and A. Campbell. 2004. Resurvey of northern abalone, Haliotis kamtschatkana, populations in southeast Queen Charlotte Islands, British Columbia, April 2002. Can. Manuscr. Rep. Fish. Aquat. Sci. 2704: 37p.

Campbell, A. (Guest Editor). 2003. Primary papers and abstracts of the proceedings of the workshop on rebuilding techniques for abalone in British Columbia. J. Shellfish Res. 22: 801-855.

Campbell, A. and L. D. Heimstra (Editors). 2003. Proceedings of the workshop on rebuilding techniques for abalone in British Columbia. Can. Tech. Rep. Fish. Aquat. Sci. 2482.

Campbell, A., J. Lessard and G.S. Jamieson. 2003. Fecundity and seasonal reproduction of northern abalone, Haliotis kamtschatkana, Barkley Sound, Canada. J. Shellfish Res. 22: 811-818.

Withler, R.E., A. Campbell, D. Brouwer, S. Li, K.J. Supernault and K.M. Miller. 2003. Implications of high levels of genetic diversity and weak population structure for the rebuilding of northern abalone populations in British Columbia. J. Shellfish Res. 22: 839-847.

Lessard J., A. Campbell, and W. Hajas. 2002. Survey protocol for the removal of allowable numbers of northern abalone, Haliotis kamtschatkana, from areas in British Columbia for use as broodstock in aquaculture. Can. Stock. Assess. Sec. Res. Doc. 2002/126: 41 p.

Withler, R., A. Campbell, S. Li, K.M. Miller, D. Brouwer and B. Lucas. 2001. High levels of genetic variation in Northern abalone (Haliotis kamstchatkana) of British Columbia. Can. Stock. Assess. Sec. Res. Doc. 2001/097: 28 p.

Campbell, A. 2000. Review of the northern abalone, Haliotis kamtschatkana, stock status in British Columbia. Can. Spec. Publ. Fish. Aquat. Sci. 130: 41-50.

Campbell, A. (Editor) 2000. Workshop on Rebuilding Abalone Stocks in British Columbia. Can. Spec. Publ. Fish. Aquat. Sci. 130. 158 p.

Gardner, J., J. Griggs and A. Campbell. 2000. Summary of a strategy for rebuilding abalone stocks in British Columbia. Can. Spec. Publ. Fish. Aquat. Sci. 130: 151-155.

Jamieson, G.S. 1999. Review of Northern, or Pinto abalone, Haliotis kamtschatkana, in Canada. Can. Stock. Assess. Sec. Res. Doc. 99/190: 22 p.

Campbell. A., I. Winther, B. Adkins, D. Brouwer and D. Miller. 1998. Survey of the Northern Abalone (Haliotis kamtschatkana) in the Central Coast of British Columbia, May 1997. Can. Stock. Assess. Sec. Res. Doc. 98/89: 28 p.

Campbell, A. 1997. Possible criteria for reopening the Northern Abalone (Haliotis kamtschatkana) fishery in British Columbia. Can. Stock Assess. Sec. Res. Doc. 97/64: 47 pp.

Campbell, A. 1996. An evaluation of abalone surveys off southeast Queen Charlotte Islands. Can. Tech. Rep. Fish. Aquat. Sci. 2089: 111-131.

Campbell, A., I. Manley and W. Carolsfeld. 1992 Size at maturity and fecundity of the abalone, Haliotis kamtschatkana, in northern British Columbia. Can. Ms. Rep. Fish. Aquat. Sci. 2169: 47-65.

Jamieson, G.S. 1989. Status of the Northen Abalone, Haliotis kamtschatkana, in Canada. Can. Feild-Naturalist 103(2):153-158.

Carolsfeld, W., S. Farlinger, B.C. Kingzett, N.A. Sloan and G. Thomas. 1988. Abalone resurvey in the southeast Queen Charlotte Islands, June 1987. Can. Ms. Rep. Fish. Aquat. Sci. 1966: 90 p.

Sloan, N.A. and P.A. Breen. 1988. Norhtern Abalone, Haliotis kamtschatkana in British Columbia: Fisheries and Synopsis of Life History Information. Canadian Special Publication of Fisheries and Aquatic Sciences 103.

Boutillier, J.A., W. Carolsfeld, P.A. Breen, S. Farlinger, and K. Bates. 1985. Abalone resurvey in the southeast Queen Charlotte Islands, July 1984. Can. Ms.. Rep. Fish. Aquat. Sci. 1818: 87 p.

Boutillier, J.A., W. Carolsfeld, P.A. Breen, and K. Bates. 1984. Abalone survey in the Estevan Group and Aristazabal Island, May 1983. Can Ms.. Rep. Fish. Aquat. Sci. 1747: 60 p.

Contacts

Abalone Staff:

Joanne Lessard
250-729-8364
Joanne.Lessard@dfo-mpo.gc.ca

Doug Brouwer
250-756-7258
Doug.Brouwer@dfo-mpo.gc.ca