Welfare Assessment of Invertebrates: Adapting the Animal Welfare Assessment Grid (AWAG) for Zoo Decapods and Cephalopods

Abstract

Consumer demand for invertebrates is on the rise as their numbers in the wild dwindle. However, with the growing conservation efforts of modern zoos and aquariums, and evidence from over 300 studies showing that invertebrates are capable of sentience, public interest, and moral concern for welfare of invertebrates have increased. The challenge for zoos and aquariums is in developing an objective and repeatable method for evaluating welfare that can be applied to invertebrates in zoological collections. Recently introduced into zoological collection management is the Animal Welfare Assessment Grid (AWAG). The AWAG helps to identify negative and positive welfare states, through assessing animal- and environmental-based indicators to make changes that lead to a better quality of life. Originally developed for the assessment of laboratory primates, the system has been successfully adapted to assess a variety of taxa across different environments, facilitated by the development of cloud-based software. In this study, the AWAG has been adapted to assess the cumulative lifetime experience of captive decapods and cephalopods at two different institutions, Marwell Zoo and National Marine Aquarium. This study has provided further evidence that the AWAG is adaptable and demonstrates the first time any objective scoring system has been successfully adapted for use in invertebrates. Through graphical representation, the results show that the AWAG identifies changes in welfare scores that can be attributed to specific events and can be used to predict the future vulnerability of species to welfare changes and suggest alternative management methods. This monitoring tool provides a versatile method of implementing practical welfare monitoring in zoos and aquariums.

Keywords: animal welfare assessment grid; captive lifetime experience; cephalopod; decapod; invertebrates; public aquaria; quality of life; sentience; welfare; zoological collections.

Figure 1

Study subjects. (A) Red-clawed crayfish Cherax quadricarinatus, housed in (B) Marwell Zoo’s tropical house. (C) NMA’s squat -lobster Galathea strigosa housed in (D) Plymouth Sound 6 tank (PS-6). (E) NMA’s shore-crab Carcinus maenas, initially housed in Temperate Quarantine (TQ) and moved to (F) during the trial period. (G) NMA’s cuttlefish Sepia officinalis housed in (H) PS-3 with two male cuttlefish and NMA’s (I) common octopus Octopus vulgaris, had access to three tanks interconnected by tubes (J). (Photos provided by NMA staff, 2021).

Figure 2

Averaged animal welfare assessment grids of the decapod (top row) and cephalopod (bottom row) study subjects. The radar charts represent the average scores for physical, psychological, environmental, and procedural parameter class over the study period on a scale from 1 to 10, with 1 being the best possible score and 10 the most detrimental. The axes in the figure are adjusted to increase clarity of the average score for each parameter class for each species. The area of the polygon presented on the radar chart equates to the CWAS value for the complete study period.

Figure 3

Daily cumulative welfare assessment scores over time for each of the three decapod species (A) crayfish, (B) shore crab, (C) squat lobster, and the two cephalopod species (D) common octopus and (E) cuttlefish. Annotation of the graphs indicates events that occurred around the time the peak in welfare score was noted (increased value indicates reduction in welfare). A line of general trends is displayed for the days that data were not collected.

Figure 3

Daily cumulative welfare assessment scores over time for each of the three decapod species (A) crayfish, (B) shore crab, (C) squat lobster, and the two cephalopod species (D) common octopus and (E) cuttlefish. Annotation of the graphs indicates events that occurred around the time the peak in welfare score was noted (increased value indicates reduction in welfare). A line of general trends is displayed for the days that data were not collected.

Figure 3

Daily cumulative welfare assessment scores over time for each of the three decapod species (A) crayfish, (B) shore crab, (C) squat lobster, and the two cephalopod species (D) common octopus and (E) cuttlefish. Annotation of the graphs indicates events that occurred around the time the peak in welfare score was noted (increased value indicates reduction in welfare). A line of general trends is displayed for the days that data were not collected.

Figure 4

Daily average parameter welfare assessment scores over time for MZ crayfish. Each line presents one of the four assessed parameters: physical, psychological, environmental, procedural, on a scale of 1 to 10. In the figure, the axes are adjusted based on the range of the daily average parameter scores. The black arrows indicate the noticeable parameter changes between two events that incur greater (i.e., suboptimal) welfare scores presented with the cuttlefish assessment.

Figure 5

Individual animal welfare assessment grid of the common octopus, the parameter scores of the two greatest peaks in the data. (A) shows the parameter scores when a change of keeper and late feeding occurred, (B) shows the presence of the same different keeper but a normal feeding time. The shape of the polygon in each is the same but at different magnitudes of change.