Category: Recovery Plans
Published: September 2021
Author(s): Kathleen Sowul, Henry S. Carson, Joshua V. Bouma, and David A. Fyfe
Pinto abalone (Haliotis kamtschatkana) is an iconic species of marine snail found in kelp forests along coastal waters. Among the seven abalone species found off the west coast of North America, pinto abalone are the only species found in Washington State. They serve an essential role in kelp forest environments as grazers, “cleaning” subtidal rock surfaces and allowing new kelp to settle. Their flavorful meat and beautiful shells also made them a highly sought-after shellfish for harvesters since time immemorial. In the recent past, the pinto abalone harvest brought sport fishers to the San Juan Islands (SJI) and Strait of Juan de Fuca (SJDF) and supported an economically significant fishery for Washington. However, by the early 1990’s their population in Washington waters had drastically declined beyond the point of sustaining an annual fishery.
Although the pinto abalone state fishery was officially authorized in 1959, subtidal pinto abalone population surveys only became possible in the late 1970s. Post-fishery abalone surveys revealed the population continued to decline well after legal harvest of the species ended. In 2013, two petitions were submitted to NOAA requesting the addition of pinto abalone to the federal endangered or threatened species list under the Endangered Species Act (ESA). In December 2014, a 12-month comprehensive status review concluded that the species was not in danger of extinction throughout all or a significant portion of its range. The Status Review Team did, however, agree and acknowledge that depensatory processes and resulting recruitment failure were a specific concern for Washington pinto abalone (Neuman et al. 2018). By 2017, abalone survey results showed a 97% decline in densities at 10 permanent survey sites around the San Juan Islands (Carson and Ulrich 2019). In 2019, after a status review by WDFW (Carson and Ulrich 2019), pinto abalone were added to the Washington State Endangered Species List.
This document is the Washington Department of Fish and Wildlife’s Pinto Abalone Recovery Plan. It identifies the recovery goal for WDFW and its partners, specifies population targets for reclassification, and outlines strategies and tasks necessary to meet the recovery goal. This plan also describes the essential partnerships and collaborations needed to restore this subtidal shellfish species back to a self-sustaining, healthy population. This document does not directly address the status of pinto abalone populations in Washington relative to recovery criteria. That will occur during the next status review, to take place every five years since the initial listing in 2019.
Populations of pinto abalone in Washington are presently well below the presumed minimum density threshold (presumed lowest density at which abalone populations achieve reproductive success) of 0.30 individuals per m-2 that allows successful reproduction (Carson and Ulrich 2019). Furthermore, based on an increasing mean shell length in surveys, and few observations of juvenile abalone in recent years, it is apparent that populations are aging without significant replacement by new generations. Pinto abalone face actual and potential threats from illegal harvest, predation, loss of kelp forests as habitat and food, changing ocean conditions, introduced diseases or parasites, and oil or contaminant spills (see Section I). There are several knowledge gaps that must be filled in order to achieve downlisting goals. These include understanding specific habitat requirements that promote survival and retention, improving husbandry techniques, exploring the impacts of ocean acidification, measuring population genetics, and understanding the relationship between adult density and fertilization efficiency (see Section III).
Effective recovery of pinto abalone will require not only a halt of population decline but an increase in population density and habitat occupancy. Given the low densities, it seems unlikely that such an increase will be possible without an active supplementation program that relies on restocking hatchery raised abalone into the wild. Until populations are above a minimum density for natural reproduction, and size structure observations indicate strong recruitment, pinto abalone in Washington are at risk of local extinction. WDFW and partners including the Puget Sound Restoration Fund (PSRF) have worked on active restoration of pinto abalone since 2002. Restoration efforts to date have included the foundation and maintenance of an abalone hatchery, the outplanting of 40,000 juvenile abalone onto 21 sites in the San Juan Islands. Researchers have studied abalone survival, growth, movement, and detectability using tags (Carson et al. 2019). They have explored the use of outplanting younger juveniles and competent larvae and continued to sample and analyze population genetics and disease risk (see Section II).
Washington’s recovery goal for pinto abalone is to reverse the decline of pinto abalone stocks and attain self-sustaining populations throughout regions of historic abundance in the state. Our recovery strategy includes separating SJI and SJDF into separate regions, each containing 5 subregions. Pinto abalone will be considered for downlisting to sensitive within the state when the following criteria are met:
- Thirty documented, naturally-formed spawning aggregations, each containing at least 6 pinto abalone and having an overall density of at least 0.3 abalone m-2 are located within each of the two regions. At least 4 of the 5 subregions in each region must have at least 3 spawning aggregations within their bounds to ensure that aggregations are dispersed throughout the historic range.
- In both regions, surveys of wild pinto abalone either on the 10 historic index stations or on newly monitored, naturally-formed aggregations must result in at least 30% of abalone with shell lengths less than 90 mm. This is to ensure that recent reproduction is ongoing and that the population does not only consist of older individuals.
These criteria are based on the first surveys for pinto abalone in the San Juan Islands which took place in 1979. The number of identified aggregations and their size distribution is not representative of the unfished population but is presumed to represent a self-sustaining state prior to widespread loss of reproductive output. A minimum 360 abalone (6 per aggregation, 30 aggregations per region, 2 regions) would not be sufficient for downlisting. However, due to the abalone’s cryptic behavior and limitations of dive surveys, each identified individual or aggregation is assumed to represent others that are not documented, in both the 1979 data on which the criteria are based and the modern surveys. Therefore, we stipulate that these aggregations must be documented, and set a five-year expiration date for each survey to allow for rotational surveying of parts of each region while maintaining current information. To meet the goal of self-sustaining populations, aggregations formed with hatchery-origin abalone will not count toward this downlisting criterion but are meant to support it by increasing reproduction in the wild. Criteria for downlisting from the current Endangered status to Threatened status use similar criteria, with thresholds of 15 aggregations per region spread over at least 3 subregions, and a size distribution with at least 15% smaller than 90 mm shell length (see section IV).
Monitoring abalone populations is quite unlike most wildlife monitoring methods used for endangered species in Washington. Since pinto abalone are found in the subtidal zone between 3 and 20 meters depth, advanced scientific scuba diving and boating skills and experience are required. Due to the limitations in time underwater for scuba divers, monitoring is highly time sensitive. To maximize efficiency, divers split into teams and conduct multiple dives per day; each dive lasting approximately 1 to 1.5 hours. Additionally, the strong tidal exchanges in the San Juan Islands and Strait of Juan de Fuca require advanced planning to ensure dive safety and limit available windows for dive work.
This recovery plan intends to achieve downlisting goals through hatchery supplementation, intensive monitoring, and scientific research. This includes ongoing efforts to maximize hatchery production through efficient rearing techniques, and to increase hatchery capacity with the development of satellite growout facilities. It includes continued outplanting of hatchery-origin juveniles with the goal of creating adult spawning aggregations throughout the SJI and SJDF. The outplanting program will continue to investigate factors that promote juvenile survival on certain sites and explore the outplanting of younger stages. Research is needed to fill identified knowledge gaps, which may also include monitoring of a changing kelp forest community. Enforcement inspections of recreational and commercial dive harvest are key to protecting remnant wild and restored aggregations. Outreach to the public and building new partnerships is necessary to achieve downlisting goals. Currently, WDFW and existing partners do not have the financial or staff resources to undertake all facets of the expanding recovery effort identified herein (see Sections V and VI).
Despite the challenging field work environment, WDFW and partners have made major strides towards reaching pinto abalone recovery goals. We believe this plan will guide continued advances in research and restoration of this species in Washington.
Sowul, K., H.S. Carson, J.V. Bouma, D. A. Fyfe. 2021. Draft Washington State Recovery Plan for the Pinto Abalone. Washington Department of Fish and Wildlife, Olympia. 53+iv pp.