Wildlife Conservation Research at AZA-Accredited Public Aquariums in North America

Zoos and Aquariums in North America have evolved over the past few decades from institutions that exhibit animals primarily for public enjoyment to conservation organizations whose mission is to inspire and contribute significantly to wildlife conservation. The Association of Zoo and Aquariums, AZA, accredits public institutions in North America that house wildlife based on strict industry standards of exhibitry, husbandry, veterinary medicine and education. The role of conservation research has evolved in AZA facilities from just a handful of staff participating in a few projects to many facilities now having entire departments dedicated to conservation research. In 2003, AZA institutions reported in the Annual Report on Conservation Science (ARCS) that 83% of its member’s participated in over 2,370 conservation projects in 107 countries and spent $77 million (AZA ARCS 2003). More recently the 2014 ARCS report stated that AZA institutions dramatically increased their conservation efforts from 2010 with 88% of members participating in conservation projects and spending 154 million. Many of the top accredited aquariums have strong conservation programs and are spending at least 3% of their budgets on conservation efforts with projects focusing on species and ecosystems and topics of global concern such as climate change and marine debris.

Nine years of rockfish surveys in the Strait of Juan de Fuca

For decades, biologists from the Seattle Aquarium have been informally monitoring bottom fish on rocky reefs in Neah Bay, Washington. Based on increasing concern over the long term stability of bottom fish populations in this area by both state and federal agencies, the Aquarium formalized monitoring in 2005 with diver-based video surveys to quantify bottom fish (rockfish and lingcod) diversity and abundance over time. Divers performed 100-meter video transects, devised to be non-invasive and repeatable, to assess diurnally active and relatively sessile bottom fishes over time. Transects were conducted in the Strait of Juan de Fuca each year in August from 2005-2013 at five permanently marked sites. Density and diversity of bottom fish species were determined by biologists counting fish via the archived video. Over the past nine years, there has been no significant difference in diversity and density of adult rockfish among sites or years, but there have been significant young of the year (YOY) rockfish recruitment events in 2006, 2008 and 2010, termed “jackpot recruitment events”. We also found that young of the year rockfish densities in the “jackpot” years were significantly correlated with lower sea surface temperatures. Rockfish recruitment may be generally poor because larval survival and settlement are dependent upon changing conditions such as climate, abundance of predators, oceanic currents, and chance events. Being long-lived allows the adult population to persist through many years of poor reproduction until a good recruitment year occurs, as in 2006, 2008 and 2010.This study may elucidate significant trends in rockfish diversity and abundance, that will influence long term management plans for rockfish conservation

Assessment of fecal glucocorticoid metabolites of cortisol and corticosterone in captive sea otters, Enhydra lutris

Glucocorticoid hormones in blood are frequently measured as indicators of vertebrate stress response. Sea otters (Enhydra lutris), common in zoos and aquariums, have been documented to secrete both cortisol and corticosterone from adrenal glands. Animals under human care allow for longitudinal study, and non-invasive collection of samples are a priority to the Seattle Aquarium. Glucocorticoid hormones are secreted, metabolized, and excreted in feces. Fecal samples can be collected opportunistically without contaminating the sample with a stress response from handling or taking blood. These samples are often coupled with extensive environmental and medical health notes, which can retrospectively link peaks with major events. The goal of this study was to determine baseline levels for individual sea otters of both sexes and a variety of ages. At the Seattle Aquarium, hormone metabolite groups were measured using commercially available ELISA kits, and validation was achieved by parallelism and accuracy tests. The aquarium has a multiyear dataset of fecal glucocorticoid metabolites for captive sea otters and there was high variation between individuals. Total overall, baseline and peak levels varied over time for each animal. Female otters baseline cortisol levels ranged from 30 - 66 ng/gr dry weight (dw), while corticosterone levels ranged from 45 – 71 ng/gr dw. Male otter baseline cortisol levels ranged from 33 – 59 ng/gr dw, while corticosterone levels ranged from 30 – 41 ng/gr dw. Differences between animals indicate individual responses to stimuli and peaks above baseline for each animal indicate specific adrenal responses. These values can provide insight for husbandry and welfare of these marine mammals as baseline levels are unknown for this species and sample type

A Temporal Analysis of Water Quality Variability at the Seattle Aquarium in Elliott Bay, Puget Sound, WA

The Seattle Aquarium is centrally located on Elliott Bay in Puget Sound, built on a pier along the central waterfront in Seattle, WA, USA. The Seattle Aquarium Water Quality Laboratory regularly measures water quality metrics on incoming saltwater pumped directly from Elliott Bay for use in the animal exhibits. This study provides a descriptive temporal analysis of variability in the incoming saltwater conducted from 2007 through 2016. Parameters measured on a weekly basis include ammonia (NH3), nitrite (NO2), pH and fecal coliform bacteria. Ammonia mean throughout the dataset was 0.02 mg/l (SE ± 0.0005), with clear seasonal trends of higher ammonia levels during the summer months (May, June and July) annually. Nitrite mean was 0.01 mg/l (SE ± 0.002), with clear seasonal trends of this nutrient with bi-annual peaks in spring and fall (May and September). Saltwater pH mean was 7.81 (SE ± 0.004), trending lower in winter and spring and higher in summer and fall. Fecal coliform bacteria mean over the 10-year period was 20 colony-forming units (CFU) per 100 ml of water. Overall, Elliott Bay water quality remained relatively stable from 2007 to 2016, and if remains unchanged, will continue to be a reliable source of saltwater with known water quality parameters for use in animal exhibits in the Seattle Aquarium

Are otters toxic? A trial in using enzyme-linked immunosorbent assays (ELISAs) to measure contaminants in sea and river otter diet and feces

The Puget Sound has been inundated with toxic contaminants for decades. As a highly urbanized body of water, contaminants are easily brought into the ecosystem through a variety of methods including runoff, air transport, industrial and residential use. The Seattle Aquarium is located centrally within downtown Seattle, and utilizes sand filtered Puget Sound seawater for use in the sea otter exhibit, and sand and carbon filtered ozonated freshwater for the river otter exhibit. This study was a trial in using enzyme-linked immunosorbent assays (ELISAs) to measure four chemicals in captive sea otter and river otter feces, a variety of diet items, sediment and water. Four chemicals were chosen for testing and included polybrominated diphenyl ethers (PBDEs, a flame retardant used in furniture and electronics, many forms currently banned in WA), polychlorinated biphenyls (PCBs, an industrial chemical banned in 1979 but persists in the environment to this day), glyphosate (Round Up, a common household herbicide) and pyrethroids (a common insecticide). Diet items include restaurant quality fish, clams and mussels sourced from around the world. Each of the samples were mixed, dried, methanol extracted and run on each ELISA test. Preliminary results show that river otter fecal samples have slightly higher values than sea otters, across the four metrics. Of the diet samples, capelin have higher PCB values (average 408 ppb), surf clams have higher pyrethroid values (average 2,815 ppb), and mussels have higher glyphosate (12 ppb) and PBDE values (288 ppb). Next steps include validation with using GC/MS. Ultimately, the Seattle Aquarium will use this data for animal healthcare, but also to inform the public about contaminants in Puget Sound and the hazards to wildlife

Observations on abundance of bluntnose sixgill sharks, Hexanchus griseus, in an urban waterway in the Salish Sea, 2003-2012

The bluntnose sixgill shark, Hexanchus griseus, is a widely distributed but poorly understood large, apex predator. Anecdotal reports of diver-shark encounters in the late 1990’s and early 2000’s in the Pacific Northwest stimulated interest in the normally deep-dwelling shark and the reason for its presence in the shallow waters of the Salish Sea. Analysis of underwater video documenting sharks at the Seattle Aquarium’s sixgill research site on Seattle’s waterfront and mark-recapture techniques were used to identify individual sharks to answer simple questions about abundance and seasonality. Temporal changes in relative abundance in Puget Sound were reported from a controlled study site from 2003-2012. At the Seattle Aquarium study site, 45 sixgills were observed and tagged with modified Floy visual marker tags, along with an estimated 116 observations of untagged sharks. Mark/Recapture statistical model estimates based on video observations ranged from a high of 98 sharks observed in July of 2004 to a low of 0 sharks observed in several research events from 2008-2012. Both analyses found sixgills significantly more abundant in the summer months at the Aquarium’s research station from 2003-2005 than at any other time during the study

Relative Abundance of Sixgill Sharks (Hexanchus griseus) in Elliott Bay, Seattle, Washington

The Sixgill Shark Research Project is designed to address gaps in the body of scientific knowledge on bluntnose sixgill sharks (Hexanchus griseus) in Puget Sound. This project utilizes three interwoven techniques: (1) genetics research, (2) visual marker tagging, and (3) video analysis. Seattle Aquarium biologists monitor sixgill shark sightings reported by local divers (since 1999) and study their relative abundance in Elliott Bay under the Aquarium’s pier (since 2003). Here we report on our findings of relative abundance. Bluntnose sixgills are a species of conservation concern. Sixgills are listed as “near threatened” on the IUCN Red List. Living mainly at abyssal depths but also in the shallow waters of the Salish Sea, sixgills are thought to be long-lived and slow-growing, and appear to have established movement corridors and home ranges that remain relatively fixed over time. As apex predators they are important members of marine communities; and, owing to their life history characteristics such as a slow rate of maturity and low reproductive rates, are thought to be extremely vulnerable to exploitation. Here we present our findings of relative abundance of sixgill sharks in Elliot Bay during the two time periods that the research was conducted: 2003-2005 and 2008-2015. We present the number of individual sharks seen each night, number of sharks tagged, number of returning tagged sharks, sex ratios, estimated number of sixgills residing in Elliott Bay (using capture-mark-recapture techniques), and seasonal and long-term trends in abundance

Genetic Diversity and Population Parameters of Sea Otters, \u3cem\u3eEnhydra lutris\u3c/em\u3e, before Fur Trade Extirpation from 1741–1911

All existing sea otter, Enhydra lutris, populations have suffered at least one historic population bottleneck stemming from the fur trade extirpations of the eighteenth and nineteenth centuries. We examined genetic variation, gene flow, and population structure at five microsatellite loci in samples from five pre-fur trade populations throughout the sea otter’s historical range: California, Oregon, Washington, Alaska, and Russia. We then compared those values to genetic diversity and population structure found within five modern sea otter populations throughout their current range: California, Prince William Sound, Amchitka Island, Southeast Alaska and Washington. We found twice the genetic diversity in the pre-fur trade populations when compared to modern sea otters, a level of diversity that was similar to levels that are found in other mammal populations that have not experienced population bottlenecks. Even with the significant loss in genetic diversity modern sea otters have retained historical structure. There was greater gene flow before extirpation than that found among modern sea otter populations but the difference was not statistically significant. The most dramatic effect of pre fur trade population extirpation was the loss of genetic diversity. For long term conservation of these populations increasing gene flow and the maintenance of remnant genetic diversity should be encouraged