Theis, S.*  Koops, M. and M.S. Poesch. (2022) A meta-analysis on the effectiveness of offsetting strategies for harm to freshwater fishes. Environmental Management 70(5): 793-807.

Abstract:

Offsetting aims to compensate for negative impacts due to authorized anthropogenic impacts. While anchored into legislation through extensive frameworks across many countries, residual or chronic impacts can occur after offset establishment for example because of the ephemeral timescale of some projects. Advice and best practice on how to approach these impacts is rare. To address this, we reviewed 30 projects based on a systematic review and meta-analysis in freshwater ecosystems dealing with residual or long-term negative impacts to provide application advice for the three main identified approaches of: habitat creation, habitat restoration and biological and chemical manipulation. Project information was obtained from scientific databases and grey literature through Boolean search terms and web-scraping. Habitat creation projects, mainly targeting salmonids, had a pooled effect size of 0.8 and offsetting ratios of 1:5 with high biomass increases of over 1.4x compared to pre-establishment, associated with them. Habitat restoration projects targeted a wide range of species and communities with a pooled effect size of 0.66, offset ratios ranging from 1:1.2 to 1:4.6, and biomass increases generally > 1x compared to pre-restoration. Biological manipulation had the lowest effect size (0.51) with stocking efforts being highly variable both in terms of biomass benefits and project outcomes pointing towards stocking being mostly applicable in cases of direct fish harm not related to environmental degradation or habitat loss. Many projects targeted salmonid species and application for a wider range of species needs to be further assessed. We conclude that 1) all three assessed approaches have a potential application use for offsetting Residual or Chronic Harm with approach specific caveats. 2) time to record first benefits required one to two years with time lags needing to be accounted for in the implementation and monitoring process, 3) monitoring timeframes of more than four years and conducting pre-assessments increased projects success significantly. Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

Citation: Theis, S.  Koops, M. and M.S. Poesch. (2022) A meta-analysis on the effectiveness of offsetting strategies for harm to freshwater fishes. Environmental Management 70(5): 793-807.

Also Read:

Theis S.*, and M.S. Poesch (2022) Current capacity, bottlenecks, and future projections for offsetting habitat loss using mitigation and conservation banking in the United States. Journal for Nature Conservation 67:126159.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Theis S.*, and M.S. Poesch (2022) Assessing conservation and mitigation banking practices and associated gains and losses in the United States. Sustainability 14: 6652.

Abstract:

Conservation and mitigation banks allow proponents to buy credits to offset negative residual impacts of development projects with the goal of No net loss (NNL) in ecosystem function and habitat area. However, little is known about the extend to which bank transactions achieve NNL. We synthesized and reviewed 12756 transactions in the United States as to meeting area and ecological equivalence (n = 4331) between approved negative impact and offset. While most transactions provided an offset equal or greater in area than the impacted area, approximately one quarter of transactions, especially targeting wetlands, did not meet ecological equivalence between impact and offset. Missing ecological equivalence was often due to the significantly increasing use of preservation, enhancement, and rehabilitation over creating new ecosystems through establishment and re-establishment. Stream transactions seldom added new ecosystem area through creation but mainly used rehabilitation to add offset benefits, in many cases leading to net loss of area. Our results suggest that best practice guidance on habitat creation as well as incentivization of habitat creation must increase in the future to avoid net loss trough bank transactions and meet the ever-accelerating global changes in land-use and the increase pressure of climate change. Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

Citation: Theis, S.  and M.S. Poesch. (2022) Assessing conservation and mitigation banking practices and associated gains and losses in the United States. Sustainability 14: 6652.

Also Read:

Ruppert, J.L.W.*, Hogg, J., and M.S. Poesch. (2018) Community assembly and the sustainability of habitat offsetting targets in the first compensation lake in the oil sands region in Alberta, Canada. Biological Conservation 219: 138-146.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Congratulations to Karling Roberts and Taylor Lund for their paper which was “Highly Commended” for the FSBI Huntingford Medal!

Congratulations to Karling Roberts and Taylor Lund, whose paper (citation below) was listed as one of two papers Highly Commended for FSBI Huntingford Medal!

  • Roberts, K.N., Lund, T., Hayden, B. and S. Poesch (2022) Season and species influence stable isotope ratios between lethally and non-lethally sampled tissues in freshwater fish. Journal of Fish Biology 100(1): 229-241. (link

Dutra, M.C.F., Pereyra, P.E.R., Hallwass, G., Poesch, M.S. and R.A.M. Silvano. (2023). Fishers’ knowledge on trophic ecology and of the tropical ‘super fish’ Plagioscion squamosissimus in two Brazilian Amazonian rivers. Neotropical Ichthyology 21(1): e220041.

Abstract:

Fishers’ local ecological knowledge (LEK) can provide new data on fish trophic ecology. The pescada (Plagioscion squamosissimus) is among the most caught fishes in small-scale fisheries in the Brazilian Amazon. Our main goal was to evaluate the abundance, size, relevance to small-scale fisheries and trophic ecology (diet and feeding interactions) of P. squamosissimus in the Tapajós and Tocantins rivers, in the Brazilian Amazon, utilizing  data from fishers’ LEK and fish sampling. We hypothesized a higher abundance, size and more prey and predators cited by fishers of P. squamosissimus in the more pristine Tapajós River. We interviewed 61 and 33 fishers and sampled fish in nine and five sites in the Tapajós and Tocantins Rivers, respectively, in 2018. The comparison between fishers’ citations and fish sampled indicated a higher relevance of P. squamosissimus to fishers in the Tapajós River, where this fish had an average larger size and where the interviewed fishers mentioned more food items of P. squamosissimus. These results show that P. squamosissimus is a generalist fish, that is resilient to fishing and environmental pressures, as well as being important to fisheries and food security, and that LEK can provide useful insights to fisheries managers. Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

Citation: Dutra, M.C.F., Pereyra, P.E.R., Hallwass, G., Poesch, M.S. and R.A.M. Silvano. (2023). Fishers’ knowledge on trophic ecology and of the tropical ‘super fish’ Plagioscion squamosissimus in two Brazilian Amazonian rivers. Neotropical Ichthyology 21(1):e220041.

Also Read:

Pereyra, P.E.R, Hallwas, G., Poesch, M.S. and R. Silvano (2021) ‘Taking fishers’ knowledge to the lab’: an interdisciplinary approach to understand fish trophic relationships in the Brazilian Amazon. Frontiers in Ecology and Evolution.

*Lab members: Mark Poesch. Check out opportunities in the lab!