Roles of Aquatic Invertebrates in Ecosystem Processes

Dr. Sohini Bhattacharyya

Assistant professor, Department of Zoology

Aquatic ecosystems cover a large area globally and provide habitat for numerous macro and microbial species (Covich et al. 1999, Liu et al. 2022). Aquatic ecosystems can vary structurally; however, the major ecosystem functions of these ecosystems remain the same. These ecosystems are also hubs for various ecosystem functions and contribute substantially towards many biogeochemical cycles (Baxter et al. 2012). Along with plants and planktons, invertebrates are an integral part of these ecosystems. Many invertebrates like mayflies, etc. require aquatic habitats to complete a portion of their life cycles. These macroinvertebrates are often abundant in such ecosystems forming a dominant portion of the biomass of the respective waterbody.

The aquatic invertebrates play numerous roles and execute critical ecosystem functions in the same. They are involved in secondary production and are major contributors to the aquatic food chain and food webs. Members of higher trophic levels are dependent on them for their diet. They play an important role in degradation and decomposition of organic debris (leaf litter, twigs, logs, etc.) along with the microbes present in the aquatic ecosystems. Aquatic macroinvertebrates like crayfish, mayflies, Chironomus, etc. are also capable of performing bioturbation which impacts the ongoing biogeochemical processes (Nitrogen, Carbon, Phosphorus, etc.) in the benthos (Chakraborty et al. 2022, Jonsson and Sponseller 2021). Macroinvertebrates in aquatic ecosystems are also known to harbour different types of bacterial taxa in their guts and the enclosed gut environment with distinct physicochemical properties can trigger processes like nitrous oxide production via denitrification and antibiotic resistance (Bhattacharyya et al. 2023).

Despite all the above-mentioned roles of the aquatic macroinvertebrates, research work related to such diverse areas in which they are involved remains scarce till date. Therefore, the contribution of aquatic macroinvertebrates towards ecosystem functioning is still a “blackbox”. However, in order to have a holistic understanding about the structural and functional attributes of aquatic ecosystems, we need to gain insights about the contribution of these aquatic macroinvertebrates.

References:

Bhattacharyya, S., Eagar, A.C., Engohang‐Ndong, J. and Leff, L.G., 2023. Antibiotic resistance gene abundance and bacterial community composition in macroinvertebrates of an urban stream. Freshwater Biology.

Chakraborty, A., Saha, G.K. and Aditya, G., 2022. Macroinvertebrates as engineers for bioturbation in freshwater ecosystem. Environmental Science and Pollution Research, 29(43), pp.64447-64468.

Covich, A.P., Palmer, M.A. and Crowl, T.A., 1999. The role of benthic invertebrate species in freshwater ecosystems: zoobenthic species influence energy flows and nutrient cycling. BioScience, 49(2), pp.119-127.

Jonsson, M. and Sponseller, R.A., 2021. The role of macroinvertebrates on plant litter decomposition in streams. The ecology of plant litter decomposition in stream ecosystems, pp.193-216.

Baxter, A.M., Johnson, L., Edgerton, J., Royer, T. and Leff, L.G., 2012. Structure and function of denitrifying bacterial assemblages in low-order Indiana streams. Freshwater Science, 31(2), pp.304-317.

Liu, S., Yu, H., Yu, Y., Huang, J., Zhou, Z., Zeng, J., Chen, P., Xiao, F., He, Z. and Yan, Q., 2022. Ecological stability of microbial communities in Lake Donghu regulated by keystone taxa. Ecological Indicators, 136, p.108695.