Regional coral responses to climate disturbances and warming is predicted by multivariate stress model and not temperature threshold metrics

Oceanic environmental variables derived from satellites are increasingly being used to predict ecosystem states and climate impacts. Despite the concerted efforts to develop metrics and the urgency to inform policy, management plans, and actions, few metrics have been empirically tested with field data for testing their predictive ability, refinement, and eventual implementation as predictive tools. In this study, the abilities of three variations of a thermal threshold index and a multivariate stress model (MSM) were used to predict coral cover and community susceptibility to bleaching based on a compilation of field data from Indian Ocean reefs across the strong thermal anomaly of 1998. Field data included the relative abundance of coral taxa 10\ua0years before the large-scale temperature anomaly, 2\ua0years after (1999–2000), and during the post-bleaching recovery period (2001–2005) were tested against 1) a multivariate model based on 11 environmental variables used to predict stress or environmental exposure (MSM), 2) estimates of the time until the current mean maximum temperature becomes the mean summer condition (TtT), 3) the Cumulative Thermal Stress (CTS) for the full satellite record, and 4) the 1998 Annual Thermal Stress (1998 ATS). The MSM showed significant fit with the post-1998 cover and susceptibility of the coral community taxa (r = 0.50 and 0.31, respectively). Temperature threshold indices were highly variable and had relatively weak or no significant relationships with coral cover and susceptibility. The ecosystem response of coral reefs to climatic and other disturbances is more complex than predicted by models based largely on temperature anomalies and thresholds only. This implies heterogeneous environmental causes and responses to climate disturbances and warming and predictive models should consider a more comprehensive multiple parameter approach

Strategies for Reduction of Poaching in Community-Based Holothurian Aquaculture

The aquaculture of Holothuria scabra has been identified as a highly potential alternative livelihood for the coastal communities of Southwest Madagascar. Despite the fact that the projects‚ results continue to improve, poaching in the pens remains a major threat to the future sustainability of the sector. With well-established market prices and trade routes, the risk of theft is particularly high, and the success of such a project is dependent of the mitigation of this threat. In light of this Blue Ventures and its partners have developed several mechanisms to limit the risks of poaching. Through the promotion of a security guard system with the necessary tools, the design of legal tools based on local conventions within the Velondriake LMMA where the project is being implemented, and engaging the national authorities, theft management has been improved. Better results for farmers, and several cases in which thieves have been identified and persecuted can testify to the efficacy of better poaching management. However within a context of weak governance, high levels of corruption, and increasing illegal collection of holothurians, sea cucumber aquaculture continues to present challenges, especially when compared to other mariculture projects such as red seaweed farming, other potential coastal communities alternative livelihood. This presentation tackles this case study, provides tools for those interested in developing sea cucumber aquaculture, and raises awareness about the potential risks of poaching for the further development of the sector.Keywords: Fisheries Economics, Posters and Game Demonstration Session and Reception, Special Topic

Community based aquaculture in the western Indian Ocean: Challenges and opportunities for developing sustainable coastal livelihoods

The small-fisheries social-ecological system in the western Indian Ocean (WIO) represents a typical social-ecological trap setting where very poor natural resources dependent coastal communities face local and global threats and engage in unsustainable practices of exploiting limited resources. Community-based aquaculture (CBA) has been implemented as an important alternative or supplementary income generating activity for minimizing the overdependence on marine natural resources and promoting biodiversity conservation. Despite its proliferation throughout the WIO region in recent decades, little is known about the degree to which CBA activities have contributed to achieving the objectives of breaking the cycle of poverty and environmental degradation and promoting community development and biodiversity conservation. In order to improve understanding of common challenges and to generate recommendations for best practice, we assessed the most common CBA activities practiced in the region through literature review and workshop discussion involving practitioners and key stakeholders. Findings indicated that despite favorable environmental conditions for various CBA practices, the sector remains underdeveloped, with few activities delivering the intended benefits for coastal livelihoods or conservation. Constraints included a shortage of seed and feed supplies, low investment, limited technical capacity and skills, insufficient political support, and lack of a clear strategy for aquaculture development. These are compounded by a lack of engagement of local stakeholders, with decision making often dominated by donors, development agencies, and private sector partners. Many of the region’s CBA projects are designed along unrealistically short time frames, driven by donors rather than entrepreneurs, and so are unable to achieve financial sustainability, which limits the opportunity for capacity building and longer-term development. There is little or no monitoring on ecological and socioeconomic impacts. Except for a few isolated cases, links between CBA and marine conservation outcomes have rarely been demonstrated. Realizing the potential of CBA in contributing toward food security in the WIO will necessitate concerted investment and capacity strengthening to overcome these systemic challenges in the sector. Lessons herein offer managers, scientists, and policy advisors guidance on addressing the challenges faced in building strategic development initiatives around aquaculture in developing countries

Temporal Change and Fishing Down Food Webs in Small-Scale Fisheries in Morondava, Madagascar

Small-scale fisheries (SSFs) are often undervalued and unmanaged as a result of a lack of data. A study of SSFs in Menabe, western Madagascar in 1991 found diverse catches and a productive fishery with some evidence of declining catches. Here we compare data collected at the same landing site in 1991 and 2011. 2011 had seven times greater total monthly landings due to more people fishing and higher individual catches. Catch composition showed a lower mean trophic level in 2011 indicating overfishing, the true extent of which may be masked due to changes in technology and fishing behaviours. Limited management action since 2011 means these trends have likely continued and an urgent need for both greater understanding, and management of these fisheries remains if they are to continue providing food and income for fishing communities

Seasonal dynamics of coral reef algae in the southern Red Sea. Functional group and population ecology.

The presence of extreme summer conditions in the southern Red Sea provides a unique opportunity to address questions on the importance of strong seasonality and extreme high temperatures in structuring coral reef communities. The main theme of this thesis is to investigate the effects of the extreme seasonality on reef algal community structure and the dynamics of different algal functional form groups, as well as on the population ecology of dominant species in the shallow reef environment.

Community Based Aquaculture in the Western Indian Ocean: Challenges and Opportunities for Developing Sustainable Coastal Livelihoods

The small-fisheries social-ecological system in the western Indian Ocean (WIO) represents a typical social-ecologicaltrap setting where very poor natural resources dependent coastal communities face local and global threats and engage in unsustainable practices of exploiting limited resources. Community-based aquaculture (CBA) has been implemented as an important alternative or supplementary income generating activity for minimizing the overdependence on marine natural resources and promoting biodiversity conservation. Despite its proliferation throughout the WIO region in recent decades, little is known about the degree to which CBA activities have contributed to achieving the objectives of breaking the cycle of poverty and environmental degradation and promoting community development and biodiversity conservation. In order to improve understanding of common challenges and to generate recommendations for best practice, we assessed the most common CBA activities practiced in the region through literature review and workshop discussion involving practitioners and key stakeholders. Findings indicated that despite favorable environmental conditions for various CBA practices, the sector remains underdeveloped, with few activities delivering the intended benefits for coastal livelihoods or conservation. Constraints included a shortage of seed and feed supplies, low investment, limited technical capacity and skills,insufficient political support, and lack of a clear strategy for aquaculture development. These are compounded by a lack of engagement of local stakeholders, with decision making often dominated by donors, development agencies, and private sector partners. Many of the region's CBA projects are designed along unrealistically short time frames, driven by donors rather than entrepreneurs, and so are unable to achieve financial sustainability, which limits the opportunity for capacity building and longer-term development. There is little or no monitoring on ecological and socioeconomic impacts. Except for a few isolated cases, links between CBA and marine conservation outcomes have rarely been demonstrated. Realizing the potential of CBA in contributing toward food security in the WIO will necessitate concerted investment and capacity strengthening to overcome these systemic challenges in the sector. Lessons herein offer managers, scientists, and policy advisors guidance on addressing the challenges faced in building strategic development initiatives around aquaculture in developing countries

Seasonal module dynamics in Sargassum subrepandum (Fucales, Phaeophyta)

Module dynamics of the fucoid alga Sargassum subrepandum (Forssk.) C. Agardh was studied in the southern Red Sea. Seasonal variation in thallus density and size was determined, and the initiation, growth, reproduction, and shedding of modules (primary laterals) were ascertained, using a tagging approach. Possible effects of different size-related parameters on module initiation, growth, reproduction, and shedding were analyzed in the context of contradicting results for other macroalgae, in comparison with terrestrial plants. Thallus density varied little; most of the seasonal variation occurred at the modular level. A restricted period of new module formation early in the cooler season was followed by fast growth and reproduction. Massive shedding of modules occurred toward the end of the cooler season leading to strongly reduced biomass in summer. There was some evidence that high module numbers inhibited new module formation and enhanced the maximum module elongation rate (fastest-growing module per thallus). On the other hand, elongation rates generally decreased, and apical tissue losses increased with increasing module length. This response was observed over a wide size range, suggesting grazing losses. There was no evidence of suppressed growth in small modules due to intraspecific competition. Elongation rates remained unaffected by reproductive status, indicating that there was no direct trade-off between growth and reproduction. Module survivorship was independent of module number and size, but fertile modules were more persistent than vegetative ones. We conclude that module dynamics are determined by seasonal changes in the environment, size-dependent processes, and interactions among the modules