Effectiveness of five small Philippines’ coral reef reserves for fish populations depends on site-specific factors, particularly enforcement history

Community-managed, no-take marine reserves are increasingly promoted as a simple, precautionary measure to conserve biodiversity and sustain coral reef fisheries. However, we need to demonstrate the effects of such reserves to those affected by the loss of potential fishing grounds and the wider scientific community. We surveyed changes in fish communities in five small marine reserves in the central Philippines and three distant Control sites over seven years. We conducted underwater visual censuses of 53 fish families within the reserve (Inside), with a kilometre of the boundary (Outside) and at Control sites. We found significant differences between fish communities Inside and Outside the reserve only at the two sites with strictest compliance with fishing prohibition, while there were significant differences to distant Control sites in all cases. The strongest responses to reserve protection were found in predatory fishes (groupers and breams) and in butterflyfish. Other abundant fish families showed weak effects of protection. For all taxa analysed, we found significant effects of reserve Site and Site × Treatment interactions. The detection of fish responses to reserves is complicated by potential spillover effects, site-specific factors, particularly compliance, and the difficulty of identifying appropriate control areas.     

Growth and condition index of mussel Mytilus galloprovincialis in experimental integrated aquaculture

Integrating mussel and finfish aquaculture has been recognized as a way to increase profits and decrease environmental impacts of finfish aquaculture, but not enough is known about the effects of finfish aquaculture on mussel growth. Here we present a pilot study aimed at determining how distance from finfish aquaculture affects mussel growth. To this end, we measured growth and condition index of mussel (Mytilus galloprovincialis) at three different distances (0, 60 and 700 m) from finfish aquaculture in the eastern Adriatic Sea. There was a statistically significant difference in growth of tagged mussels with respect to site. Average measured lengths of mussels at sites 1, 2 and 3 after the 10 months of the experiment were 57.60, 62.73 and 58.66 mm. Mussels grew fastest from March to May, and slowest from July to September, regardless of their position. Condition index showed spatial and temporal variations with higher values during fall and winter (∼23), and lower values during spring and summer (∼20). Our results show that production cycle in areas traditionally considered suboptimal for aquaculture can be equivalent to the cycle in areas traditionally considered optimal for mussel aquaculture if mussel aquaculture is integrated with finfish aquaculture.     

Fishing groupers towards extinction: a global assessment of threats and extinction risks in a billion dollar fishery

Groupers are a valuable fishery resource of reef ecosystems and are among those species most vulnerable to fishing pressure because of life history characteristics including longevity, late sexual maturation and aggregation spawning. Despite their economic importance, few grouper fisheries are regularly monitored or managed at the species level, and many are reported to be undergoing declines. To identify major threats to groupers, the International Union for Conservation of Nature (IUCN) Red List criteria were applied to all 163 species. Red List assessments show that 20 species (12%) risk extinction if current trends continue, and an additional 22 species (13%) are considered to be Near Threatened. The Caribbean Sea, coastal Brazil and Southeast Asia contain a disproportionate number of Threatened species, while numerous poorly documented and Near Threatened species occur in many regions. In all, 30% of all species are considered to be Data Deficient. Given that the major threat is overfishing, accompanied by a general absence and/or poor application of fishery management, the prognosis for restoration and successful conservation of Threatened species is poor. We believe that few refuges remain for recovery and that key biological processes (e.g. spawning aggregations) continue to be compromised by uncontrolled fishing. Mariculture, through hatchery‐rearing, increases production of a few species and contributes to satisfying high market demand, but many such operations depend heavily on wild‐caught juveniles with resultant growth and recruitment overfishing. Better management of fishing and other conservation efforts are urgently needed, and we provide examples of possible actions and constraints.     

Aspergillus niger and a Penicillium sp. are not directly involved in the degradation of chlorsulfuron

When Aspergillus niger or a Penicillium sp. were grown in potato dextrose broth supplemented with chlorsulfuron, the herbicide concentration decreased by 97–99% within 78–96 h and the pH of the medium fell from 7.2 to between 2.4 and 3.1. If, during growth, the pH was maintained at or near neutrality, no decrease in herbicide concentration occurred. When sterile medium containing the herbicide was titrated with acid to mimic acid formation during fungal growth, the herbicide concentration again declined. Precipitation was not responsible for the observed decrease. The data indicate that, in laboratory media, these fungi do not directly metabolise the herbicide as previously thought. Chlorsulfuron degradation in perfused soil cores was not enhanced by inoculation with A. niger. Our results show that A. niger and a Penicillium sp. do not degrade chlorsulfuron.     

The potential for aquaculture of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) in southern Croatia

To assess the potential of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) for aquaculture in southern Croatia, we analyzed their survival and growth rates under two experimental conditions—suspended culture and on-bottom culture. Furthermore, we investigated feeding on zooplankton by these two species in suspended culture conditions and compared them with previously published results of their feeding on zooplankton in the natural benthic environment. Experimental studies were conducted in Mali Ston Bay (Adriatic Sea) from December 2009 to December 2010. Differences were observed in terms of survival of tagged M. barbatus and A. noae—specimens of M. barbatus exhibited much better survival rates both in suspended culture and in on-bottom cages than did A. noae. Growth of A. noae under both culture conditions was essentially negligible, while M. barbatus grew several times faster in suspended culture than on the bottom. Values for the growth constant K and L _inf for M. barbatus in suspended culture were 0.45 year^?1 and 55.9 mm, while corresponding values for on-bottom culture were 0.09 year^?1 and 58.6 mm, respectively. Zooplankters were present in the stomachs of 86.3 % of M. barbatus and 86.4 % of A. noae. Most abundant taxa were bivalve larvae followed by tintinnids, copepods, unidentified eggs and gastropod larvae. In conclusion, this study clearly shows that M. barbatus is a promising candidate for suspended aquaculture in southern Croatia.