Abundance of a cryptic generalist parasite reflects degradation of an ecosystem

Abstract

Ecosystem degradation due to anthropogenic activities is the primary issue of our times. Theoretical analyses as well as efforts to restore and manage ecosystems depend on comprehensive metrics of ecosystem function. In the case of complex ecosystems such as tropical coral reefs-especially where monitoring, management, and restoration are important-multiple metrics reflecting key functional groups are required to accurately reflect ecosystem function and when necessary, diagnose degree and kind of ecosystem degradation. We propose inclusion of the generalist ectoparasite functional group as a measure of ecosystem function of coral reefs. This functional group is adaptable to loss of other community members and may experience an increase in abundance as ecosystem function declines. Fish-parasitic gnathiid isopods are a member of this group, resident though inconspicuous in coral-reef communities. On Caribbean coral reefs, based on 938 light-trap samples, we observed a negative correlation between abundance of smallersized gnathiids and abundance of live coral, a natural predator of gnathiids. Plots grouped by coral cover-a measure of success of the ecosystem engineer-and ectoparasite abundance varied significantly in community composition including abundance of macroalgae, turf algae, and farming Stegastes spp. damselfish reflecting shifts in community structure. Changes in gnathiid abundance with respect to the abundance of organisms participating in each of the core functional processes driving coral-reef ecosystems reflect broad connectivity of gnathiid parasites across the ecosystem. We conclude that the hyperabundance of a small, cryptic, generalist parasite, when used in combination with a metric of abundance of the primary ecosystem engineer, can provide one nuanced measure of the ecosystem vulnerability to collapse.

Prevalence of Stony Coral Tissue Loss Disease at El Seco, a Mesophotic Reef System off Vieques Island, Puerto Rico

“…is limited or non-existent on coral reefs (Rogers et al, 1984;Edmunds and Elahi, 2007;Irizarry-Soto and Weil, 2009;Hernández-Delgado et al, 2014). Therefore, the extensive and chronic loss of these corals could have dramatic impacts not only on the diversity but to the ecosystem function of El Seco, as many fish, invertebrates and cryptofauna use these habitats as refuge (Artim et al, 2020).…”

“…High diversity of fish, corals, sponges, and cryptofauna in MCEs occur at rocky discontinuities (outcrops, ledges, etc. ) and along the upper depth zone (Pyle and Copus, 2019;Sherman et al, 2019;Artim et al, 2020). These ecosystems are prime residential, foraging, mating, nesting, and seasonal spawning aggregation habitats for a wide variety of commercially valuable fishes and shellfishes (García-Sais et al, 2020).…”

Habitat and Client Diversity Influence the Skin Microbiome of the Caribbean Cleaner Goby Elacatinus Evelynae

“…Despite the high diversity of clients visiting cleaning stations in West Lameshur, not only did cleaners from that location have similar bacterial alpha-diversity levels to the ones from Brewers Bay and Hull Bay, but they also showed a contrasting relation between microbial diversity and cleaning activity when compared to the gobies in the other reefs. A possible explanation for the differences found in West Lameshur might be related to the greater habitat degradation at this sampling locality [30], which could have altered local reef community dynamics. Although reef animal communities harbor some of the most diverse microbial communities of the marine environment [42], it is estimated that the changes in host communities in a given location may impact microbial diversity in the entire reef [43].…”

“…Interestingly, those differences include contrasting results from sh captured from different reef habitats within less than 500 m of each other. Even though they are located within the same bay, Donkey Bight and West Lameshur differ in coral cover [30]. Additionally, a mangrove swamp empties out near West Lameshur site, and therefore water quality parameters and reef communities are likely to vary among our sites [53], leading to differences in sh microbial consortia.…”

“…1). Donkey Bight is dominated by a mix of rocky reef, live and dead coral, sand, and seagrass, while West Lameshur is highly degraded with almost no live coral, and it is located near a mangrove swamp [30].…”