The tropical Pacific Oceanscape: Current issues, solutions and future possibilities.

Marine ecosystems across the world's largest ocean - the Pacific Ocean - are being increasingly affected by stressors such as pollution, overfishing, ocean acidification, coastal development and warming events coupled with rising sea levels and increasing frequency of extreme weather. These anthropogenic-driven stressors, which operate cumulatively at varying spatial and temporal scales, are leading to ongoing and pervasive degradation of many marine ecosystems in the Pacific Island region. The effects of global warming and ocean acidification threaten much of the region and impact on the socio-cultural, environmental, economic and human health components of many Pacific Island nations. Simultaneously, resilience to climate change is being reduced as systems are overburdened by other stressors, such as marine and land-based pollution and unsustainable fishing. Consequently, it is important to understand the vulnerability of this region to future environmental scenarios and determine to what extent management actions can help protect, and rebuild ecosystem resilience and maintain ecosystem service provision. This Special Issue of papers explores many of these pressures through case studies across the Pacific Island region, and the impacts of individual and cumulative pressures on the condition, resilience and survival of ecosystems and the communities that depend on them. The papers represent original work from across the tropical Pacific oceanscape, an area that includes 22 Pacific Island countries and territories plus Hawaii and the Philippines. The 39 papers within provide insights on anthropogenic pressures and habitat responses at local, national, and regional scales. The themes range from coastal water quality and human health, assessment of status and trends for marine habitats (e.g. seagrass and coral reefs), and the interaction of local pressures (pollution, overfishing) with increasing temperatures and climate variability. Studies within the Special Issue highlight how local actions, monitoring, tourism values, management, policy and incentives can encourage adaptation to anthropogenic impacts. Conclusions identify possible solutions to support sustainable and harmonious environment and social systems in the unique Pacific Island oceanscape.

Promoting sustainable and inclusive oceans management in Pacific islands through women and science.

The question of how to efficiently and effectively manage ocean resources in a sustainable way has reached the forefront of discussion at an international level, but women's contributions to this process have been underestimated or unrecognized. Inclusive management plays a major role in the effective creation, use and adoption of environmental governance, necessitating efforts to measure, monitor and advance inclusivity. In many Pacific island states, there is a lack of disaggregated data collection and management to assist reliable and liable gender-responsive decision-making by national and regional authorities. This lack of information leads to unquantified female contributions and unexplored potential for women to actively contribute to sustainable ocean management as traditional leaders, researchers or science-based managers and in accordance with traditional customs, cultures and processes. This paper examines the contribution of gender-disaggregated data in both (1) effective management of natural resources and (2) measurement and monitoring of the active involvement of women in ocean management. We seek to shift the question from simply "(How) are oceans used by women?" to "How can we build a clear path towards inclusive oceans management using science?", drawing data mainly from gender and ocean management practices in Pacific Small Island Developing States. This work also seeks to ground in reality the increasing national and international evocations about social equity and avoidance of gender discrimination. Given the existing relationships of Pacific peoples with the ocean and the emerging status of ocean science-based governance, wider integration of science and women in marine management can make an interesting and positive impact in this region.

Recruitment density can determine adult morphology and fecundity in the barnacle, Semibalanus balanoides.

Although consequences of the settlement preference of larvae have been well documented, the consequence of these settlement choices on subsequent mortality, morphology and fecundity has been little studied. The aim of this study was to determine the relationship between recruit and adult density and to determine the effect of recruitment on adult morphology and egg tissue mass. This study follows 48,718 barnacles (Semibalanus balanoides) from recruitment at the end of the settling season to reproductively mature adults at a field site in the Clyde Sea (UK). Overall survivorship of the recruits to adulthood was 8.5%, although survivorship was up to 42% on low density settlement panels. In low density colonies (< 10 recruits cm-2), recruitment density was related to adult density (P < 0.001), whereas no relationship was found for higher density colonies. A shell morphology index measured at adulthood was related to recruitment density for low density recruited colonies (P < 0.001) but not high density colonies. Using ANCOVA, variations between the colonies in shell and egg tissue mass were not explained by mass of somatic tissue. However, egg mass was explained by recruitment density (P < 0.01). These results show that adult density is not a reliable indicator of the previous population density of the colony. Moreover, there are marked differences in population development between colonies with high and low recruit densities in terms of impact upon shell morphology and egg production. The dynamics that operate between recruits at the end of the settlement season and sexually mature adults to create the patterns elucidated in this paper, and other literature, remain unclear.