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Climate, ocean acidification, and the changing oceans

Room: Boisdale     2014-08-15; 15:00 - 17:00

NB: Unless specified otherwise, presentations are 15 minutes in length, and speed presentations are 5 mins in length.

Chair(s)/Moderator(s): Aguilar de Soto, Natacha

C5.1  15:00  Anthropogenic noise causes body malformations and delays development in marine . Natacha Aguilar de Soto *, University of La Laguna; Natali Delorme University of Auckland; John Atkins University of Auckland; Sunkita Howard University of Otago; James Williams NIWA; Mark Johnson University of St Andrews;

Abstract: Marine invertebrates at the base of oceanic trophic webs play important ecological and economic roles in supporting worldwide fisheries worth millions. There is increasing concern about the effects of anthropogenic noise on marine fauna but little is known about its effects on invertebrates, which may range from apparently null through behavioral/physiological responses to mortalities. Here we show that scallop larvae exposed to playbacks of seismic pulses showed significant developmental delays and 46% developed body abnormalities. Similar effects were observed in all independent samples exposed to noise while no malformations were found in the control groups (4881 larvae examined). Malformations appeared in the D-veliger larval phase, perhaps due to the cumulative exposure attained by this stage or to a greater vulnerability of D-veliger to sound-mediated physiological or mechanical stress. Such strong impacts suggest that abnormalities and growth delays may also result from lower sound levels or discrete exposures during the D-stage, increasing the potential for routinely-occurring anthropogenic noise sources to affect recruitment of wild scallop larvae in natural stocks. The results are presented in the context of the scarce peer-reviewed literature on the effect of noise on marine invertebrates emphasizing the need to consider potential interactions of human activities using intense sound sources with the conservation and fisheries of local invertebrate stocks.

C5.2  15:15  Projecting changes to the relative abundance, distribution, and richness of First Nations’ culturally-important marine species under climate change. Weatherdon, L *, Fisheries Centre, University of British Columbia; Cheung, WWL Fisheries Centre, University of British Columbia; Ota, Y Fisheries Centre, University of British Columbia;

Abstract: Recent studies have demonstrated ways in which climate-related shifts in the distribution and abundance of marine species are expected to alter the dynamics and catch potential of global fisheries. While potential commercial impacts have been explored, few efforts have been made to quantitatively estimate potential impacts to small-scale fishing communities that are economically, socially, and spiritually sustained through their relationships with the marine environment. To address this knowledge gap, we used the Dynamic Bioclimate Envelope Model (DBEM) to project scenarios of climate-related changes to the relative abundance, distribution and richness of 100 marine and diadromous species that are of commercial and cultural importance to First Nations situated along coastal British Columbia, Canada. These results were then used to estimate impacts to fisheries relative catch potential and associated economic and nutritional contributions to local communities. Findings illustrate a substantial shift in species’ relative abundance, distribution, and richness between 2000 and 2050 (using twenty-year averages) in relation to First Nations’ traditional territories, leading to a decline in the availability of many traditional foods. Our study highlights potential adaptation opportunities accompanying invasive species, the need to consider conservation strategies that could assist with reallocations of fishing pressure, and the implications for First Nations’ treaty allocations.

C5.3  15:30  Human impacts on the size structure of Pacific coral reef fish communities. James Robinson *, University of Victoria; Andrew Edwards Fisheries and Oceans Canada; Ivor Williams Pacific Islands Fisheries Center; Rusty Brainard Pacific Islands Fisheries Center; Julia Baum University of Victoria;

Abstract: Human disturbances have wide ranging and diverse impacts on coral reef ecosystems. Reductions in biomass and biodiversity are well documented, particularly at local scales, and yet the impacts on community structure are less defined. Size-based analyses can be used to describe changes to community structure where, by quantifying the allometric relationship between body size and abundance, the size spectrum represents the distribution of body sizes in a community. Exploitation of large body sizes alters community structure and is reflected by a steepening of the size spectrum. Here, using an extensive dataset of fish abundance and body size at over 50 Pacific islands, covering several biogeographic regions, we explore the variation in community structure attributable to human impacts. Size spectra of populated reefs are steeper than their near-pristine, uninhabited counterparts, indicating a consistent and ocean-basin wide effect of fishing on the reef fish community. Size based analyses complement the use of diversity and biomass metrics in teasing out the impacts of human disturbances on marine ecosystems.

C5.4  15:45  Global assessment of extinction risk in anemonefishes and the suitability of IUCN criteria for habitat specialist marine species. De Brauwer, M *, Scool of Plant Biology, The University of Western Australia; Hobbs, JP Oceans Institute, The University of Western Australia; Harvey, E Department of Environment and Agriculture, Curtin University;

Abstract: Anemonefishes are iconic coral reef fishes and these reefs are threatened by increasing anthropogenic impacts. All 28 species of anemonefishes have an obligate symbiotic relationship with up to 10 species of anemones, making them highly vulnerable to habitat destruction. To determine which anemonefish species have the highest risk of extinction a global database was constructed on the distribution and abundance of host anemones and anemonefishes across their entire geographic ranges. Data was collected from surveys of more than 5 600 000 m² of coral reef involving more than 4300 transects across 84 locations and 25 countries. Anemonefishes occur in very low abundances across their respective ranges and even the most abundant anemonefish has less than two adults per 250m². Two of the endemic species were not observed in any transects (N = 150). Global percent cover for the 10 host anemone species (combined) on coral reefs is less than 0.5% (and less than 0.05% for most species). The extremely limited availability of habitat restricts the abundance of anemonefishes. Applying the relevant IUCN criteria, up to 50% of anemonefishes could be categorised as “Threatened”, with endemics having the highest risk of extinction. However, applying IUCN criteria to habitat specialist marine species is problematic, but needs addressing because these species are also the most affected by habitat destruction.

C5.5  16:00  Population dynamics of a tropical seabird facing climate change: the case of Audubon’s shearwater in a natural reserve of Martinique. PRECHEUR, C *, phD student; BRETAGNOLLE, V researcher ;

Abstract: Effect of climate change on tropical regions is of high interest since it has been much less studied than in temperate regions. Top marine predators, such as seabirds, are good indicators since they usually of impacts of climate change on marine environment. In this context, we here assess the demographic trends and traits in a small colony of Audubon\'s shearwater Puffinus lherminieri lherminieri from Martinique between 1995 and 2013. This colony is of high conservation interest since the Caribbean taxon is currently considered as threatened. After quantifying demographic parameters through CMR analyses, we used population viability analyses to simulate the demographic response in regard to climate change (based on GICC scenarios). Using mark-recapture methods and two data sets (one on adult birds, the other on fledglings) We found an mean annual estimate for juvenile survival of 0.58 ±0.23 (SE), and 0.83 ±0.025(SE) for both adult and immature survival rates, while that of birds of unknown age was 0.80± 0.019(SE). We found a significant positive effect of sea surface temperature (SST) on survival rate (ANODEV, p=4.10-4), that we interpret by a strong influence of Amazon and Orinoco rivers on the lesser Antilles’s marine productivity. A deterministic simulation model provide a declining trend for the colony (λ=0.93). We discuss how these findings may support the current policy for managing this important marine areas and guides future studies on potential risks at sea such as fisheries and oil spills.

C5.6  16:15  Can specimen of the cold-water coral Desmopyllum dianthus adapt to a changing environment in the Chilean Fjord Region? Henry Goehlich *, University of Rostock; Jürgen Laudien Alfred-Wegner-Institute Helmholtz-Center for Polar and Marine Research; Christopher Nowak University of Bremen; Carin Jantzen Alfred-Wegner-Institute Helmholtz-Center for Polar and Marine Research; Vreni Häussermann Huinay Scientific Field Station ; Claudio Richter Alfred-Wegner-Institute Helmholtz-Center for Polar and Marine Research;

Abstract: The cold-water coral Desmophyllum dianthus naturally grows under low natural pH conditions. Using the buoyancy-weight technique, a 12-months in situ growth experiment revealed that CaCO3 precipitation was 0.34 ± 0.15 kg m-2 yr-1 equal to a skeleton dry mass increase of 0.05 ± 0.02 % d-1. A cross-transplantation experiment with specimens collected from two sites within fjord Comau with distinct pH (center: 7.76, mouth: 7.94) was conducted to describe the adaptability of D. dianthus to calcify under different pH. Control and transplanted corals originated from the site with the lower pH showed a significant higher percentage [Tukey-Kramer test, p = 0.009) of dry mass increase. Our video record with a remotely operated vehicle (ROV) revealed corals living between 20 and 270 m in a wide range of pH values (pH 7.6–8.4). This proofs that D. dianthus can thrives in a pH range of at least 0.8 units. However, other environmental parameters e.g. hypoxia or increased sedimentation may severely affect this important ecosystem engineer; a recent coral mass mortality caused a decline in abundance of Cape redfish (Sebastes capensis). Extensive aquaculture and the planned construction of a road along the fjord Comau are potential strong threads for this unique ecosystem. Since D. dianthus banks are only present in the fjords Comau, Reñihué Reloncaví, and Piti Palena and are hotspots of biodiversity their conservation is an urgent need.

C5.7  16:30  Conservation planning for coral reefs to account for disturbance related to climate change. Magris, RA *, Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University – JCU; Heron, SF National Oceanic & Atmospheric Administration Coral Reef Watch; Marine Geophysical Laboratory, School of Engineering and Physical Sciences, James Cook University ; Pressey, RL Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University ;

Abstract: Incorporating climate-change impacts into the design of marine protected areas (MPAs) is fundamental to developing appropriate conservation actions to confer ecosystem resilience. Considering the current uncertainty about the ability of corals to cope with these impacts, we evaluated the extent to which no-take MPAs in Brazil include coral-reef areas exposed to various thermal stress regimes. Data on sea-surface temperature for 25 years were used to derive indices of acute and chronic thermal stress, based on “degree heating weeks” and rate of warming through regression analyses, respectively. We evaluated how well existing no-take MPAs: 1. protect areas that have been less exposed to both types of thermal stress; 2. might enhance survival through future thermal stress of corals that have not experienced severe acute events; and 3. support stress-tolerant species. Areas relatively unaffected by climate-related disturbances (lowest acute and chronic stress) are entirely unprotected. About 37% of the areas under high chronic but low acute stress are within no-take zones; those areas can increase the chance of survival of corals through anticipated future stress. Conversely, no-take zones covered only 2% of areas that might contain resistant coral species (highest acute and chronic stress). Conservation objectives based on both historical and predicted thermal regimes will improve the design of MPAs by avoiding or mitigating climate-change impacts.

C5.8  16:45  Heat tolerance in the African Penguin in the face of climate change. Tubbs, NC *, Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa; Pichegru, L Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa; Ryan, PG Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa; Green, JA School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK;

Abstract: The African Penguin was classified as ‘Endangered’ by the IUCN in 2010, due to the loss of 70% of its population in the last decade. Habitat loss from former guano scraping is a major issue as it exacerbates heat stress. Historically, most African Penguins bred in guano burrows that provided a buffered microclimate and shelter from predators. During very high temperatures, adults may leave their nests to cool down in the sea. This is often fatal for broods in surface nests due to predation and exposure. Since climate change increases extreme weather, the situation is worsening. Previous studies indicate that these effects can be reduced by artificial nests. However, whether they can fully replace natural burrows is still unknown. This study seeks to 1) pinpoint the temperature where heat stress begins, 2) understand behavioral responses to temperature, 3) estimate inter-colony temperature differences, 4) determine how extreme weather affects breeding success and 5) evaluate the effectiveness of artificial nests. Although the study is ongoing, preliminary results show that the heat stress point of African penguins is 28.6 ± 0.3 °C (lower than similar species). Behavior data show that heat stress may be occurring more often and at lower air temperatures than predicted, from the influence of weather or artificial nest design. The results of this study will help to predict how populations may be affected by climate change, as well as informing management actions to limit impacts.

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