Welfare General Session Abstracts
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On the use of statistical modeling
in making data informed husbandry decisions R you ready!?
Point Defiance Zoo & Aquarium
In 2018 the new Pacific Seas Aquarium at Point Defiance Zoo and Aquarium opened which includes a 280,000-gallon exhibit featuring scalloped hammerhead sharks, green sea turtles and spotted eagle rays. Soon after opening the Elsmobranch team began noticing negative behavioral issues in the shark collection that were on track to lead to poor husbandry outcomes. One hammerhead shark was chronically rubbing against the front window causing mechanical damage to its cephalofoil whilst another had developed a Fusarium sp. fungal infection which is very often fatal. Before the situation worsened, the team wanted to better understand and mitigate the factors driving these negative outcomes. Fortunately, the team had been collecting behavioral data from the time the sharks were introduced which enabled robust statistical analysis. Significant factors affecting shark behavior were identified using generalized linear models. Based on model predictions changes were made that led to positive behavioral outcomes for the collection of hammerhead sharks. Ongoing data collection has enabled the team to statistically address and make data informed husbandry decisions as new issues have arisen.
Don't Blow It Up!
Improving Welfare Through Small-Scale, In-House Actions
North Carolina Aquarium
on Roanoke Island
Aquatic animal welfare is an increasingly vital aspect of aquarium science, but significant challenges may occur in modifying existing habitats and infrastructure in the name of animal welfare. These modifications can be both time consuming and cost prohibitive. The need for upgrades and improvements is a never-ceasing reality of modern public aquariums. However, small and seemingly insignificant changes within an environment can provide perceptible improvement, without breaking the bank, when executed thoughtfully and purposefully.
The Stingray Touch Habitat at the North Carolina Aquarium on Roanoke Island, constructed in 2000, was increasingly displaying the need for improvement based on documented animal welfare assessments. Although no immediate welfare concerns were identified, the scores were steadily presenting lower values than other similar habitats. At the end of 2019 and into the beginning of the COVID-19 pandemic of 2020, monetary resources were limited. Creativity and resourcefulness became key to addressing these animal welfare problems within the given financial and labor limitations. By making several changes over the span of 12-18 months, we were able to measurably improve animal welfare, aesthetics, and functionality within one of our most popular attractions.
Behavioral and physiological metrics of sensory decline and
welfare in senescent giant Pacific octopus, Enteroctopus dofleini
Aquarium of the Bay
Senescent octopuses experience extreme physical decline over a period of days, weeks, or months before eventual death. Despite widely known, predictable declines in octopus health in the post-reproductive stage, evaluations of welfare and humane endpoints are not standardized, in part because little is known about sensory and neural degeneration in the terminal phase. This study measured changes in behavioral response to nociceptive stimuli over the course of senescence in giant Pacific octopus (GPO), Enteroctopus dofleini, held in public aquariums in the USA (N=9) using von Frey filaments. Post-euthanasia, tissue was collected from arm tips (N=8), neural and epithelial cell death was quantified and compared with arm biopsies of healthy, pre-reproductive (n=2) GPOs. Behavioral data showed a significant difference in threshold mechanosensory and nociceptive response between pre- and post-senescent stages (significant values p < 0.05). Cell density declined significantly between healthy and senescent GPOSs for axial ganglion neurons (p < 0.0001) and epithelial cells at the sucker edge (p = 0.0016) tissues. There was a non-significant but clear trend in epithelial tissue death on the dorsal arm (p = 0.0657). Our results indicate a pronounced increase in sensitivity to touch at the early stages of senescence, followed by a precipitous decline as GPOs near death. Additionally, declines in cellular density between healthy and perimortem GPOs suggests the loss of sensitivity seen in peri-mortem behavioral assays may be explained by overall loss of neural and epithelial sensory cells. Our data provide new insight into the physiology underlying senescence-induced behavioral changes in octopuses.