Abstracts

Coastal & Marine Communities

Enhancing the Performance of Marine Reserves in Estuaries: Just Add Water. 2017. Gilby, B.L. (University of the Sunshine Coast, Queensland, Australia, bgilby@usc.edu.au), A.D. Olds, N.A. Yabsley, R.M. Connolly, P.S. Maxwell and T.A. Schlacher. Biological Conservation 210:1–7. dx.doi.org/10.1016/j.biocon.2017.03.027

Marine reserves are an important tool for coastal conservation. Their implementation in estuaries, one of the world's most impacted and arguably important ecosystems, are seldom tested. Establishing reserves usually comes with a cost, especially for commercial and recreational fisheries. In order to avoid confrontation, reserves are often placed in "residual" locations, which in turn reduce their effectiveness. In this study, Gilby and colleagues evaluated the effectiveness of an estuarine reserve network in Eastern Australia. They sampled six no-take estuarine reserves in residual locales and compared abiotic (i.e., size, tidal estuarine width range, habitat composition) and biotic characteristics (fish assemblage, abundance and composition) to other nearby non-reserve estuaries where commercial fishing was permitted. Results showed that no-take reserves established in less impactful places did not positively affect fish abundance. Usually, reserves fail in promoting fish abundance and diversity if the habitats they support have little or no ecological value for fish, or if they represent only a small subset of the abiotic conditions present at a regional scale. The reserves analyzed here were consistently smaller, had higher proportions of intertidal sand flat cover, and were less connected to the ocean than the fished areas. The authors conclude that placing reserves in small estuaries does not aid in the protection of commercially important fish species; conservation efforts could be better directed elsewhere.

Reintroduction of a Dioecious Aquatic Macrophyte (Stratiotes aloides L.) Regionally Extinct in the Wild. Interesting Answers from Genetics. 2017. Orsenigo S., R. Gentili (University of Milano-Bicocca, Milano, Italy, rodolfo.gentili@unimib.it), A.J.P. Smolders, A. Efremov, G. Rossie, N.M.G. Ardenghi, S. Citterio and T. Abeli. Aquatic Conservation: Marine and Freshwater Ecosystems 27:10–23. doi: 10.1002/aqc.2626

A common restoration practice for locally extant species is to introduce individuals from nearby populations. Recreating the population's genetic make-up is difficult at best and can limit establishment due to founder effects. This is more important in the case of dioecious plants, where sex ratio is as critical as inbreeding potential. Stratiotes aloides (water soldiers) is a dioecious aquatic plant, threatened in Europe and currently extinct in Italy due to high nitrogen loads from agricultural runoff. S. aloides stands support high macroinvertebrate diversity and are considered a keystone species supporting several endangered vertebrate and invertebrate species. Two remnant populations in Italy exist (kept by amateur botanists), composed solely of asexually reproductive females. In this study, Orsenigo and colleagues used DNA analyses to characterize genetic patterns of these populations to determine if females were genetically diverse enough to maintain a healthy population. They sampled six natural populations throughout Europe and one ex situ population cultivated from Botanical Garden of Berlin specimen in order to determine which males were suitable for reintroduction. An unexpected level of high genetic variation in the female-only populations was reported. Investigators speculate that founder effects were absent due to increased gene flow from floating propagules or by the presence of hermaphrodite or tetraploidy plants. In terms of genetic similarity, Italian populations clustered with Romanian and Dutch populations, making these the best sources for male introduction in Italy. This study highlights the use of genetics in determining the best population selection for species reintroduction. The authors conclude that practitioners must consider sex ratio and interpopulation ecological differences prior to population restoration.

Algal Subsidies Enhance Invertebrate Prey for Threatened Shorebirds: A Novel Conservation Tool on Ocean Beaches? 2017. Schlacher, T.A. (The University of the Sunshine Coast, Maroochydore, Australia, tschlach@usc.edu.au), B.M. Hutton, B.L. Gilby, N. Porch, G.S. Maguire, B. Maslo, R.M. Connolly, A.D. Olds and M.A. Weston. Estuarine, Coastal and Shelf Science 191:28–38. dx.doi.org/10.1016/j.ecss.2017.04.004

Anthropogenic activities cause declines in numerous shore bird species...