Climate‐induced vulnerability of fisheries in the Coral Triangle: Skipjack Tuna thermal spawning habitats

We investigated projected changes in sea surface temperature (SST) and the associated impacts on spawning habitat for skipjack tuna (Katsuwonus pelamis) in the Coral Triangle region (CT). A multimodel aggregate of SST CMIP5 models for the CT region, based on a comprehensive skill validation assessment, was used to identify the five best performing of 36 models tested for inclusion in a regional multimodel ensemble. Monthly 1° SST multimodel aggregate projections for the CT region under RCP8.5 show that increases in SST, as high as 2.8°C (mean value), will likely occur by the end of this century. Using these estimates of SST change, we applied three parameterizations of skipjack tuna spawning temperatures to assess the potential for change in spawning habitat within the CT region. The three spawning temperature parameterizations were as follows: (a) a square‐wave function derived from catch data with boundaries at 26 and 30°C; (b) a symmetric Gaussian function derived from the SEAPODYM models; and (c) an asymmetric Gaussian function that modifies the SEAPODYM curve in (b) to include the results of relevant physiological experiments. All three parameterizations show similar geographic patterns, with the amount of favourable spawning habitat decreasing throughout the central, equatorial CT region and increasing at higher latitudes. However, the three parameterizations show marked differences in the modelled magnitude of change, with an asymmetric Gaussian function (ASGF) showing a regionwide average of 66.1% decline in favourable spawning habitat between 2015 and 2099. These projected changes in tuna spawning habitats are likely to have important consequences on local and regional fisheries management in the CT region.     

Atrioventricular valvular insufficiency and congestive heart failure in a carpet python

Right atrioventricular valve insufficiency and bilateral congestive heart failure were identified in a carpet python (Morelia spilota variegata) with the aid of colour Doppler echocardiography, electrocardiography and radiography. The snake failed to respond to diuretic therapy and was euthanased. Based on this case, it appears that bilateral congestive failure is feasible in univentricular animals with lesions restricted to one side of the heart. Loop diuretic therapy may be inappropriate in non-crocodilian reptiles because reptiles lack a loop of Henle.     

COMPUTED TOMOGRAPHY OF BALL PYTHONS (Python regius) IN CURLED RECUMBENCY

Anesthesia and tube restraint methods are often required for computed tomography (CT) of snakes due to their natural tendency to curl up. However, these restraint methods may cause animal stress. The aim of this study was to determine whether the CT appearance of the lungs differs for ball pythons in a curled position vs. tube restraint. Whole body CT was performed on ten clinically healthy ball pythons, first in curled and then in straight positions restrained in a tube. Curved multiplanar reformatted (MPR) lung images from curled position scans were compared with standard MPR lung images from straight position scans. Lung attenuation and thickness were measured at three locations for each scan. Time for positioning and scanning was 12 ± 5 min shorter for curled snakes compared to tube restraint. Lung parenchyma thickness and attenuation declined from cranial to caudal on both straight and curled position images. Mean lung parenchyma thickness was greater in curled images at locations 1 (P = 0.048) and 3 (P = 0.044). Mean lung parenchyma thickness decreased between location 1 and 2 by 86–87% (straight: curled) and between location 1 and 3 by 51‐50% (straight: curled). Mean lung attenuation at location 1 was significantly greater on curled position images than tube restraint images (P = 0.043). Findings indicated that CT evaluation of the lungs is feasible for ball pythons positioned in curled recumbency if curved MPR is available. However, lung parenchyma thickness and attenuation in some locations may vary from those acquired using tube restraint.     

Coral Farming: Past, Present and Future Trends

There Have Been Significant Technical Advances in Marine Aquarium Maintenance in The Last 20 Years. It is Now Possible to Maintain, Grow and Reproduce in Aquaria Many of the Coral Species Found on Coral Reefs. Due to the increased Demand For Live Corals and Other Reef Invertebrates, The Commercial Production of these Organisms for the Home Aquarium Market Has Become Feasible. This Paper Describes the Early Beginnings of Live Coral Propagation, Current Coral Propagation Facilities Located in Europe, North America, and the Pacific Basin Followed by a Discussion of an Example of the Possible Future for Coral Farming, Namely Propagation by Sexual Reproduction. Suggestions for Areas of Further Research in Captive Coral Propagation are Also Presented.     

Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia

This study examines factors affecting the rate and extent of biomass build-up among commercially important groupers, snappers, grunts, parrotfish and surgeonfish in a network of four marine reserves in southwest St. Lucia, Caribbean. Reserves constituted 35% of the total reef area originally available for fishing. Protection was instigated in 1995 after a baseline survey with annual or biennial censuses performed until 2002. Each survey consisted of 114 fifteen minute fish counts in reserves and 83 in fishing grounds, at depths of 5 m and 15 m in a 10 m diameter counting area. Estimates of number and size (cm) of target species were used to calculate fish family biomass. Data were analysed using three-way ANOVA in a before-after-control-impact pairs (BACIP) design. All families increased significantly in biomass over time at nearly all sites. Increases were greater in reserves than fishing grounds, except for grunts, and responses were strongest in parrotfish and surgeonfish. The combined biomass of families more than quadrupled in reserves and tripled in fishing grounds between 1995 and 2002. During this period coral cover declined by 46% in reserves and 35% in fishing grounds. Multiple regression showed that neither habitat characteristics nor habitat deterioration significantly affected rates of biomass build-up. The key factor was protection from fishing, which explained 44% of the variance in biomass growth. A further 28% of the variance was explained by sedimentation, a process known to stress reef invertebrates, significantly reducing the rate of biomass build-up. St. Lucia’s reserves succeeded in producing significant gains to fish stocks despite coral cover and structural complexity falling steeply over the period of the study.     

Connectivity of reef fish between mangroves and coral reefs: Algorithms for the design of marine reserves at seascape scales

Many species of coral reef fish undertake ontogenetic migrations between seagrass beds, mangroves, and coral reefs. A recent study from the Caribbean found that the availability of mangrove nursery habitat had a striking impact on the community structure and biomass of reef fish in their adult, coral reef habitat. The biomass of several species more than doubled when the reefs were connected to rich mangrove resources (defined as having at least 70 km of fringing Rhizophora mangle within a region of 200 km²). Here, the results of this large-scale empirical study are translated into a series of algorithms for use in natural resource management planning. Four algorithms are described that identify (i) the relative importance of mangrove nursery sites, (ii) the connectivity of individual reefs to mangrove nurseries, (iii) areas of nursery habitat that have an unusually large importance to specific reefs, and (iv) priority sites for mangrove reforestation projects. The algorithms generate a connectivity matrix among mangroves and coral reefs that facilitates the identification of connected corridors of habitats within a dynamic planning environment (e.g., reserve selection algorithms).     

Conservation of coral reef biodiversity: a comparison of reserve selection procedures for corals and fishes

A range of different biodiversity-based selection methods for nature reserves has been tested for terrestrial environments, including those based on diversity hotspots, endemicity hotspots and complementarity. In this study, we investigate the utility of these approaches for a coral reef embayment. We compare coral and fish species richness in a random accumulation of reserve sites with (a) hotspots analysis, (b) stratified selection of hotspots, and (c) complementarity. Cumulative species-site curves indicated that complementarity maximized the rate of accumulation of species of both corals and fishes in reserves, while the hotspot approach performed moderately well. An equivalent number of reserve sites supported a greater proportion of the coral biodiversity when compared to fishes, reflecting the broader distribution of corals. Our results indicate that when choosing an indicator group as a proxy for representing overall diversity in a reserve network, the group with the greatest heterogeneity will provide the best results. Our findings also show that although a modest number of protected sites (20%) will incorporate much of the local diversity (>75%), species-specific approaches must be incorporated to target rare species.     

Community-based conservation results in the recovery of reef fish spawning aggregations in the Coral Triangle

In the Coral Triangle community-based marine protected areas (MPAs) are being established at a prolific rate. Their establishment can benefit both fisheries and biodiversity, and they provide both a socially and economically acceptable means of managing coral reefs in developing nations. However, because such MPAs are typically small (usually <0.5 km²), they will rarely provide protection to large mobile fishes. An exception to this limitation may exist when community-based MPAs are established to protect small sites where vital processes occur, such as fish spawning aggregations (FSAs). To test the effectiveness of small (0.1–0.2 km²) MPAs for protecting FSAs, we monitored three FSA sites where brown-marbled grouper (Epinephelus fuscoguttatus), camouflage grouper (Epinephelus polyphekadion) and squaretail coralgrouper (Plectropomus areolatus) aggregate to spawn. Sites were monitored during peak reproductive periods (several days prior to each new moon) between January 2005 and November 2009. All three sites are located in New Ireland Province, Papua New Guinea, and had been exploited for decades, but in 2004 two sites were protected by the establishment of community-based MPAs. The third site continued to be exploited. Over the monitoring period densities of E. fuscoguttatus and E. polyphekadion increased at both MPAs, but not at the site that remained open to fishing. At one MPA the densities of E. polyphekadion increased tenfold. Our findings demonstrate that community-based MPAs that are appropriately designed and adequately enforced can lead to the recovery of populations of vulnerable species that aggregate to spawn.