Using ecosystem health and welfare assessments to determine impacts of wild collection for public aquariums

Abstract

Aquatic ecosystems are currently facing a multitude of stressors from anthropogenic impacts, including climate change, pollution, and overfishing. Public aquariums positively contribute to ecosystems through conservation, education, and scientific advancement; but may also negatively detract from these systems through collection of animals from the wild and sourcing from commercial suppliers. Changes within the industry have occurred, although evidence-based assessments of 1) how aquariums collect and maintain their populations to determine sustainability of the environment they have harvested; and 2) the welfare of these harvested animals once within the aquariums are still needed. The objectives of this study were to assess the ecosystem health of locations aquariums frequently visit to collect fish from the wild, and then evaluate the wellbeing of fishes at aquariums after extended periods in captivity. Assessments included use of chemical, physical, and biological indicators at field sites, and use of a quantitative welfare assessment at aquariums for comparison to species reared through aquaculture. Anthropogenic pressures at field sites were observed, but no evidence of high degradation or compromised health of animals were found. Welfare assessments of aquarium exhibit tanks produced high-positive scores overall (> 70/84), demonstrating that both wild collected (avg. score 78.8) and aquaculture fishes (avg. score 74.5) were coping appropriately within their environments. Although findings indicated that fish can be taken from the wild at low-moderate rates without any deleterious impact on the environment and cope equally well in aquarium settings, alternatives such as aquaculture should be considered as a strategy to reduce pressure on known stressed aquatic environments or where significant numbers of fishes are being taken.

Fig 1. Field site locations.

Maps of the four field sites, SC1 (32.834752, - 79.986940), SC2 (32.856259, - 79.902133), NC1 (34.692179, - 76.829056), and NC2 (34.701380, - 76.832141), from where two public aquariums collect species from for their institutions. Maps were created using ArcGIS. Contributors for the SC maps included Esri Community Maps Contributors, City of Charleston, Charleston County GIS, OpenStreetMap, Microsoft, Esri, HERE, Garmin, SafeGraph, GeoTechnologies, Inc., METI/NASA, USGS, EPA, NPS, US Census Bureau, USDA, and Maxar. Contributors for the NC maps included Esri Community Maps Contributors, State of North Carolina DOT, Esri, HERE, Garmin, SafeGraph, GeoTechnologies, Inc., METI/NASA, USGS, EPA, NPS, Census Bureau, USDA, NC CGIA, and Maxar.

Fig 2. Average field site total environmental assessment score.

Influence of field site on average total environmental assessment score (p < 0.01). Scores calculated by summing ratings 1–5 (poor–excellent) in all categories, highest achievable score = 50. **indicates p < 0.01 after post-hoc comparisons.

Fig 3. Average Shannon-Wiener diversity index for SC1 and reference periods.

Average Shannon-Wiener diversity indexes for SC1 and AR reference periods (p < 0.01). SC1 different than all AR reference periods after post-hoc comparisons (p < 0.01).

Fig 4. Average Shannon-Wiener diversity index for SC2 and reference periods.

Average Shannon-Wiener diversity indexes for SC2 and LW reference periods (p < 0.01). SC2 different than all reference periods after post-hoc comparisons (p < 0.01).

Fig 5. Average aquarium total welfare assessment score.

Influence of aquarium on average total welfare score (p = 0.01). Ratings within each category of 1–3 (high risk–good) were summed and behavior ratings weighted by multiplying scores by two. Highest achievable score = 84.