The benefits of bivalve reef restoration: a global synthesis of underrepresented species

This is the final version. Available on open access from Wiley via the DOI in this recordBivalve habitat restoration is growing in geographic extent and scale globally. While addressing the wide‐scale loss of these biogenic habitats is still a key motivation behind restoration efforts, stakeholders and funders are increasingly drawn to shellfish restoration for the many ecosystem services these habitats provide. There is clear evidence for the provision of ecosystem services from species targeted for restoration in the USA, in particular Crassostrea virginica. Ecosystem services, however, remain largely unquantified or even undescribed for the majority of other species targeted for restoration. A structured review of the literature was undertaken and supplemented by expert knowledge to identify which ecosystem services are documented in the following other bivalve species targeted for restoration: Ostrea edulis, Ostrea angasi, Crassostrea rhizophorae, Perna canaliculus, Modiolus modiolus, Mytilus edulis, Mytilus platensis, Crassostrea gigas, Ostrea denselamellosa, Crassostrea ariakensis, and Crassostrea sikamea. Key knowledge gaps in quantifying ecosystem services and the ecosystem engineering properties of habitat‐building bivalves contributing to the provision of ecosystem services were identified. Ecosystem services with the potential to be widely applicable across bivalve habitat‐building species were identified. Though there is evidence that many of the ecosystem engineering properties that underpin the provision of ecosystem services are universal, the degree to which services are provided will vary between locations and species. Species‐specific, in situ, studies are needed in order to avoid the inappropriate transfer of the ecosystem service delivery between locations, and to further build support and understanding for these emerging targets of restoration.Glenmorangie DEEP projectHWU EGISEuropean Unionerman Federal Agency for Nature ConservationEuropean Union Horizon 202

Australian shellfish ecosystems: past distribution, current status and future direction

We review the status of marine shellfish ecosystems formed primarily by bivalves in Australia, including: identifying ecosystem-forming species, assessing their historical and current extent, causes for decline and past and present management. Fourteen species of bivalves were identified as developing complex, three-dimensional reef or bed ecosystems in intertidal and subtidal areas across tropical, subtropical and temperate Australia. A dramatic decline in the extent and condition of Australia's two most common shellfish ecosystems, developed by Saccostrea glomerata and Ostrea angasi oysters, occurred during the mid-1800s to early 1900s in concurrence with extensive harvesting for food and lime production, ecosystem modification, disease outbreaks and a decline in water quality. Out of 118 historical locations containing O. angasi-developed ecosystems, only one location still contains the ecosystem whilst only six locations are known to still contain S. glomerata-developed ecosystems out of 60 historical locations. Ecosystems developed by the introduced oyster Crasostrea gigas are likely to be increasing in extent, whilst data on the remaining 11 ecosystem-forming species are limited, preventing a detailed assessment of their current ecosystem-forming status. Our analysis identifies that current knowledge on extent, physical characteristics, biodiversity and ecosystem services of Australian shellfish ecosystems is extremely limited. Despite the limited information on shellfish ecosystems, a number of restoration projects have recently been initiated across Australia and we propose a number of existing government policies and conservation mechanisms, if enacted, would readily serve to support the future conservation and recovery of Australia's shellfish ecosystems

Turning a lost reef ecosystem into a national restoration program

Achieving a sustainable socioecological future now requires large-scale environmental repair across legislative borders. Yet, enabling large-scale conservation is complicated by policy-making processes that are disconnected from socioeconomic interests, multiple sources of knowledge, and differing applications of policy. We considered how a multidisciplinary approach to marine habitat restoration generated the scientific evidence base, community support, and funding needed to begin the restoration of a forgotten, functionally extinct shellfish reef ecosystem. The key actors came together as a multidisciplinary community of researchers, conservation practitioners, recreational fisher communities, and government bodies that collaborated across sectors to rediscover Australia's lost shellfish reefs and communicate the value of its restoration. Actions undertaken to build a case for large-scale marine restoration included synthesizing current knowledge on Australian shellfish reefs and their historical decline, using this history to tell a compelling story to spark public and political interest, integrating restoration into government policy, and rallying local support through community engagement. Clearly articulating the social, economic, and environmental business case for restoration led to state and national funding for reef restoration to meet diverse sustainability goals (e.g., enhanced biodiversity and fisheries productivity) and socioeconomic goals (e.g., job creation and recreational opportunities). A key lesson learned was the importance of aligning project goals with public and industry interests so that projects could address multiple political obligations. This process culminated in Australia's largest marine restoration initiative and shows that solutions for large-scale ecosystem repair can rapidly occur when socially valued science acts on political opportunities

Time travelling through local ecological knowledge regarding an endangered species

European freshwater pearl mussel (Margaritifera margaritifera) populations are declining despite a growing effort to conserve them. Here we used a combination of local ecological knowledge (LEK) and field sampling to assess past and current distribution and conservation status of this endangered species in Cávado and Neiva Rivers (Portugal). We performed face-to-face interviews in both rivers and sampled the entire area where the respondents confirmed the historical presence of this species. Abiotic characterization, water quality and fish diversity were also assessed in both rivers. We found that freshwater pearl mussels are now possibly extinct in Cávado River but almost 50% of the respondents confirm its presence in the past, especially elders that lived in villages near its historical distribution. To the contrary, and although the species is still present in Neiva River, only 3.8% of the respondents remembered its presence in the past. In both rivers, respondents suggested pollution as the most important explanation for the freshwater pearl mussels decline. However, nowadays both rivers present excellent water quality and trout Salmo trutta (the freshwater pearl mussel fish host) is still abundant. Since we identified the areas where the species was present in a recent past, this information is vital for possible management actions with the aim of re-introduce or increase the abundance of M. margaritifera populations and/or for the rehabilitation of habitats in both rivers. We also highlight the vital importance of getting LEK, mainly from elders, in order to avoid shifting baseline syndromes and to get qualitative accurate information of past references and/or experience with historical conditions. Results reported here reinforce concern about the conservation status of freshwater pearl mussel populations in Portugal and can be used to guide future research and management initiatives to better conserve this species.This work was supported by POSEUR-03-2215-FC-000096 and ICNF funds under project CP01-MARG-QUERCUS/2018. We acknowledge André Vinhas Fernandes, Bruna Gonçalves, Maria Inês Carvalho and José Vasco for the help in doing the interviews and field work. We thank Ivan Bolotov and two anonymous referees for the valuable suggestions made, which increased the clarity of our manuscript

Conservation status of oyster reef ecosystem of Southern and Eastern Australia

Reef ecosystems all over the world are in decline and managers urgently need information that can assess management interventions and set national conservation targets. We assess the conservation status and risk of ecosystem collapse for the Oyster Reef Ecosystem of Southern and Eastern Australia, which comprises two community sub-types established by Saccostrea glomerata (Sydney rock oyster) and Ostrea angasi (Australian flat oyster), consistent with the IUCN Red List of Ecosystems risk assessment process. We established: (i) key aspects of the ecosystem including: ecological description, biological characteristics, condition and collapse thresholds, natural and threatening processes; (ii) previous and current extent of occurrence and current area of occupancy; and (iii) its likelihood of collapse within the next 50e100 years. The most severe risk rating occurred for Criterion A: Reduction in Extent (since 1750) and Criterion D: Disruption of biotic processes (since 1750), although assessment varied from Least Concern to Critically Endangered amongst the four criteria assessed. Our overall assessment ranks the risk of collapse for the ecosystem (including both community sub-types) as Critically Endangered with a high degree of confidence. Our results suggest the need for rapid intervention to protect remaining reefs and undertake restoration at suitable sites. Several restoration projects have already demonstrated this is feasible, and Australia is well equipped with government policies and regulatory mechanisms to support the future conservation and recovery of temperate oyster ecosystems

A well-kept treasure at depth: precious red coral rediscovered in Atlantic deep coral gardens (SW Portugal) after 300 years

The highly valuable red coral Corallium rubrum is listed in several Mediterranean Conventions for species protection and management since the 1980s. Yet, the lack of data about its Atlantic distribution has hindered its protection there. This culminated in the recent discovery of poaching activities harvesting tens of kg of coral per day from deep rocky reefs off SW Portugal. Red coral was irregularly exploited in Portugal between the 1200s and 1700s, until the fishery collapsed. Its occurrence has not been reported for the last 300 years.info:eu-repo/semantics/publishedVersio

Reconstructing ecological baselines: toward improved management in aquatic ecosystems

Human disturbances that alter ecosystems are distinct from natural disturbances that drive variation, and are critical to separate in the study of ecological change. Patterns created by a combination of anthropogenic and natural drivers are often ambiguous so that existing patterns can be mistakenly considered a function of natural or anthropogenic processes. Consequently, a notable challenge in ecology and in natural resource management is not only to recognise ‘change’, but also its causes. This thesis explored shifts in ecological patterns, and human perception of them, in aquatic ecosystems across historical time scales of decades to hundreds of years. Particular emphasis was given to the activities of fishing and European colonisation, which are renowned drivers of alterations. Research methods encompassing ecology, fisheries science and history, were used to generate time series for select hypotheses of change. Fisheries production and catch data were combined with historical data from the Adelaide Fish Market to reconstruct several baselines for fisheries in South Australia from colonisation in 1836 through present. Using the conceptual models of fishing down and ‘neo-Europe’ to account for change, key shifts in fisheries were identified. These were the modern addition and expansion of fisheries at lower trophic levels and the historical predilection of European settlers toward exploiting inland species. Though there is strong evidence of critical changes in ecosystems due to resource extraction, the addition or introduction of new species to ecosystems can also be influential. The effect of contemporary concern of society toward a cryptogenic oyster species and its management was assessed from a historical perspective. Field experiments were used to evaluate the impact of this species as an epibiont on a native bivalve. These established that the species might bring positive benefits, which contrasted the negative societal perception of unwanted ‘invasion’. A factor contributing to this negative perspective was diminished general memory of the past presence of oyster reefs, which have been lost from that locality. A baseline of lost oyster reefs across the South Australian coastline was reconstructed through recovering fisheries catch and effort data and building a time line of change, including declines in perceived and actual abundance of this habitat due to overexploitation during the 1800s and early- to mid-1900s. The past distribution of oyster reefs was established, along with their eradication across more than 1,500 km of the nearshore environment and loss of this knowledge through intergenerational amnesia. To account for such shifts scientists and managers can incorporate past baselines into their practice and to test this approach historical data were used to inform several aspects of planning for aquaculture. This thesis demonstrated that ecological baselines in temperate aquatic ecosystems have shifted and that more accurate representations of past states can be retrospectively reconstructed. Also, it illustrated the influence that change can have on societal and administrative perspectives and, accordingly, advocates for wider consideration of the shifting baseline syndrome. Without better representation of the past we risk misinterpreting change, negative and positive, which could perpetuate reduced expectations for the environment and its deterioration.Thesis (Ph.D.) (Research by publication) -- University of Adelaide, School of Biological Sciences, 2015

Loss of an ecological baseline through the eradication of oyster reefs from coastal ecosystems and human memory

Published online: 14 January 2015Oyster reefs form over extensive areas and the diversity and productivity of sheltered coasts depend on them. Due to the relatively recent population growth of coastal settlements in Australia, we were able to evaluate the collapse and extirpation of native oyster reefs (Ostrea angasi) over the course of a commercial fishery. We used historical records to quantify commercial catch of O. angasi in southern Australia from early colonization, around 1836, to some of the last recorded catches in 1944 and used our estimates of catch and effort to map their past distribution and assess oyster abundance over 180 years. Significant declines in catch and effort occurred from 1886 to 1946 and no native oyster reefs occur today, but historically oyster reefs extended across more than 1,500 km of coastline. That oyster reefs were characteristic of much of the coastline of South Australia from 1836 to 1910 appears not to be known because there is no contemporary consideration of their ecological and economic value. Based on the concept of a shifted baseline, we consider this contemporary state to reflect a collective, intergenerational amnesia. Our model of generational amnesia accounts for differences in intergenerational expectations of food, economic value, and ecosystem services of nearshore areas. An ecological system that once surrounded much of the coast and possibly the past presence of oyster reefs altogether may be forgotten and could not only undermine progress towards their recovery, but also reduce our expectations of these coastal ecosystems.Heidi K. Alleway and Sean D. Connel

The role of policy in supporting alternative marine farming methods: A case study of seafloor ranching in Australia

Recent attention to the ecosystem service-generating potential of marine aquaculture (mariculture) indicates that there is substantial opportunity for marine farming to optimise practices that benefit both production and nature. One strategy for augmenting sustainability within the mariculture industry is to develop more diverse farming practices and culture species that can operate within existing ocean space constraints, contribute to ecological and conservation objectives, and assuage negative public sentiment towards mariculture. While this strategy has the potential to expand mariculture's sustainability, the implementation of these alternative culture approaches will likely depend on whether the management frameworks that regulate the industry have the authority and the capacity to enable farming innovations and encourage investment in diverse mariculture systems. Using Australia and seafloor ranching of molluscs as a case study, we explore the suitability of existing policy and legislation to support novel farming methods. We find that the policy frameworks differ across States in terms of their applicability (both implicit and explicit) to seafloor ranching activities, with substantial gaps regarding the siting and building of farming infrastructure. In the context of these results, we discuss potential strategies for leveraging existing policy and management frameworks to meet the needs of seafloor ranching and identify operational stages where new, targeted policy could be particularly impactful. Our case study offers practical insights to policymakers in Australia and other countries and regions seeking to support innovations in culture methods with a greater potential for sustainability