Successful application of a novel technique to quantify negative impacts of derelict fishing nets on Northwestern Hawaiian Island reefs.

The remote and uninhabited Northwestern Hawaiian Islands (NWHI) contain 70% of the shallow water coral reefs in the United States and are regularly exposed to derelict fishing nets. These nets snag on the shallow reefs, damaging or killing benthic communities. However, no data exist to quantify this impact. Here we use a novel application of photogrammetry, Structure-from-Motion (SfM), to calculate benthic cover from mosaic images at net-impact and control sites. Net-impact sites had significantly higher cover of bare substrate, sand, and crustose coralline algae and significantly lower coral and macroalgae cover compared to control sites. These differences were unrelated to net size and fouling. Our study demonstrates the utility of using SfM to efficiently quantify impacts of derelict fishing nets. Revisiting these sites will be essential to document how the reef recovers to further our understanding of the lasting impacts of derelict fishing nets on coral reef habitats.

Long-term monitoring of coral reef fish assemblages in the Western central pacific.

Throughout the tropics, coral reef ecosystems, which are critically important to people, have been greatly altered by humans. Differentiating human impacts from natural drivers of ecosystem state is essential to effective management. Here we present a dataset from a large-scale monitoring program that surveys coral reef fish assemblages and habitats encompassing the bulk of the US-affiliated tropical Pacific, and spanning wide gradients in both natural drivers and human impact. Currently, this includes >5,500 surveys from 39 islands and atolls in Hawaii (including the main and Northwestern Hawaiian Islands) and affiliated geo-political regions of American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the Pacific Remote Islands Areas. The dataset spans 2010-2017, during which time, each region was visited at least every three years, and ~500-1,000 surveys performed annually. This standardised dataset is a powerful resource that can be used to understand how human, environmental and oceanographic conditions influence coral reef fish community structure and function, providing a basis for research to support effective management outcomes.

The Coral Triangle Atlas: an integrated online spatial database system for improving coral reef management.

In this paper we describe the construction of an online GIS database system, hosted by WorldFish, which stores bio-physical, ecological and socio-economic data for the 'Coral Triangle Area' in South-east Asia and the Pacific. The database has been built in partnership with all six (Timor-Leste, Malaysia, Indonesia, The Philippines, Solomon Islands and Papua New Guinea) of the Coral Triangle countries, and represents a valuable source of information for natural resource managers at the regional scale. Its utility is demonstrated using biophysical data, data summarising marine habitats, and data describing the extent of marine protected areas in the region.