Essay: Making the most of recent advances in freshwater mussel propagation and restoration

Abstract

Propagating and releasing freshwater mussels (Unionida) into the wild can contribute substantially to conservation and perhaps ecosystem restoration, but poorly conceived projects can waste money and public good will, and harm mussel populations and ecosystems. Moving from vague, emotional reactions about mussel restoration to more rigorous discussions and analyses can help focus efforts to where they do the most good. We suggest that: (i) projects to restore mussels for conservation goals to sites where known environmental problems have been eliminated or mitigated have good prospects for success; (ii) projects to restore mussels for conservation goals to sites where known environmental problems have not been eliminated or mitigated have poor prospects for success; (iii) projects to restore mussels for conservation goals to sites in the common situation in which the status of environmental problems is unknown have unknown prospects for success, but may be valuable as scientific experiments, if project performance is monitored properly; (iv) the value of population augmentation as a conservation tool is uncertain, and needs better theoretical and empirical analysis; (v) assisted migration of mussels as a conservation tool is controversial, and should be discussed thoroughly before we reach crises in which it is rejected or carried out carelessly; (vi) projects to restore ecosystem services face more stringent criteria for success than conservation projects, and some such projects being discussed seem unlikely to succeed. Monitoring data on how restoration projects perform typically are inadequately collected, reported, disseminated, and used to improve practice. This could be improved by setting up a clearinghouse to collect, hold, and disseminate data; providing training to restorationists; and opening conversations between restorationists and data managers and statisticians.

Conservation genomics reveals low genetic diversity and multiple parentage in the threatened freshwater mussel,Margaritifera hembeli

“…Regardless of taxon, 46 detailed genetic assessments clarify the pattern and process of diversity across a landscape, 47 diagnose specific conservation challenges, and answer crucial questions managers face during 48 the decision making process ( Roe 2017). Despite the 55 potential contribution of genetic information to successful conservation efforts, many species 56 have little or no genetic data available; this is particularly true of freshwater mussels (Haag and 57 Williams 2014; Strayer et al 2019). 58…”

“…In cases where propagation methods are actively being developed and 52 reintroduction efforts planned, genetic analysis can assist production and brood stock selection, 53 better insure successful reintroduction outcomes, and enable continued monitoring of established 54 populations (Jones et al 2006;Schwartz et al 2007; McMurray and Roe 2017). Despite the 55 potential contribution of genetic information to successful conservation efforts, many species 56 have little or no genetic data available; this is particularly true of freshwater mussels (Haag and 57 Williams 2014; Strayer et al 2019). 58…”

Fisheries Volume 45 Number 9 September 2020

“…We still raise fish for recreational fishing and as food, but fish and other aquatic organisms are also cultured as pets, biological controls, experimental models for research, and for other reasons. Fisheries management and conservation activities remain reliant on hatcheries as a critically important "leg of the fisheries management stool" Trushenski et al 2018;Strayer et al 2019), but as noted above, there is now a broader range of intended uses of hatchery-origin fish. As the reasons for propagating fish changed, so did the means of propagation.…”

Captive breeding of Margaritifera auricularia (Spengler, 1793) and its conservation importance

“…At present, one recognized way of helping to preserve these species is through captive breeding (Bolland, Bracken, Marin, & Lucas, ; Gum, Lange, & Geist, ; Moorkens, ; Preston, Keys, & Roberts, ; Strayer, Geist, Haag, Jackson, & Newbold, ). Indeed, Gum et al () stated that the captive breeding of endangered freshwater mussels can be an efficient tool to maintain the evolutionary potential of their populations, which otherwise would not resist long enough to benefit from the restoration of their habitats.…”

“…At present, one recognized way of helping to preserve these species is through captive breeding (Bolland, Bracken, Marin, & Lucas, 2010;Gum, Lange, & Geist, 2011;Preston, Keys, & Roberts, 2007;Strayer, Geist, Haag, Jackson, & Newbold, 2019).…”