Search

The ecosystem services approach to conservation is becoming central to environmental policy decision making. While many negative biological invasion-driven impacts on ecosystem structure and functioning have been identified, much less was done to evaluate their ecosystem services. In this paper, we focus on the often-overlooked ecosystem services provided by three notable exotic ecosystem engineering bivalves, the zebra mussel, the quagga mussel, and the golden mussel. One of the most significant benefits of invasive bivalves is water filtration, which results in water purification and changes rates of nutrient cycling, thus mitigating the effects of eutrophication. Mussels are widely used as sentinel organisms for the assessment and biomonitoring of contaminants and pathogens and are consumed by many fishes and birds. Benefits of invasive bivalves are particularly relevant in human-modified ecosystems. We summarize the multiple ecosystem services provided by invasive bivalves and recommend including the economically quantifiable services in the assessments of their economic impacts. We also highlight important ecosystem disservices by exotic bivalves, identify data limitations, and future research directions. This assessment should not be interpreted as a rejection of the fact that invasive mussels have negative impacts, but as an attempt to provide additional information for scientists, managers, and policymakers. [ABSTRACT FROM AUTHOR]

Ecosystem macroscopic properties given by Ascendency theoretical framework were compared between two multispecies mass-balanced trophic models of the coastal benthic ecosystem along Mejillones Bay in northern Chile (SE Pacific). The models were constructed with a similar number of components representing system conditions for years 2006 and 2018 using Ecopath with Ecosim (EwE) software. The most relevant change was that the macroalgae (principally Rhodophyta group) increased notably over 12 years. In terms of Ascendency, the larger increase in Total System Throughput (TST) compared to the null increment in the Average Mutual Information would indicate that the benthic ecosystem of Mejillones Bay is moving towards eutrophic conditions. This is consistent with the reduction in the TST cycled, Finn's cycling index, and a two-fold increase in the flow of detritus. Likewise, the Keystone Species Complex seems to be sensitive to changes in the properties of ecosystems, reducing the number of components in cases of deteriorated ecosystem. Based on the results obtained, it is suggested the implementation of management strategies that allow reversing this trend towards eutrophication, such as, to strengthen environmental policies and monitoring programs in order to conserve the benthic communities of Mejillones Bay. [ABSTRACT FROM AUTHOR]

The spatially hierarchical stream hydrogeomorphology classification presented by Cox et al. ([3]), based on 42 Irish headwater streams, is simple to apply and may be applicable across northern and western Europe with similar climate - landscape conditions. It is clear from these papers and others presented at SEFS12 that the extensive length of the small stream network and high numbers of ponds poses challenges in terms of water quality and biodiversity monitoring. Small water bodies are increasingly recognised as important for biodiversity and in terms of their influence on downstream water quality and contributions to catchment ecosystem services (Riley et al., [12]). [Extracted from the article]