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9. Fins harvested from hundreds of sharks lay drying in the sun. While fishing for sharks is not illegal for Marshallese fishers, illegal shark fishing is suspected in some areas of the Marshall Islands, such as at Mili Atoll. Photo: S. Pinca.
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The reefs of the Marshall Islands are among the most pristine in the Indo-Pacific, having suffered minimal damage from bleaching, destructive fishing techniques, and sedimentation. However, signs of unsustainable resource exploitation are apparent, including the earlier extirpation of the largest giant clams, and the ongoing reduction of reef shark...
Citations
... The RMI is a nation of 29 atolls and five oceanic islands in the northwest tropical Pacific, just north of the Gilbert Islands of Kiribati and east of the Federated States of Micronesia. The Marshallese people depend heavily on surrounding coral reefs for food, as fishing is a major source of sustenance (Gillett, 2008;Martin et al., 2017), and for protection from storms and rising seas (Pinca et al., 2005). ...
... To date, there have only been a few published studies of the RMI's coral reefs (e.g.; Houk and Musburger, 2013;Martin et al., 2017;Pinca et al., 2005;Richards et al., 2008;Richards and Beger, 2011), none of which have included Arno Atoll. Because of the close proximity to Majuro, Arno is subject to some fishing pressure by fishermen who travel from Majuro, but this is almost entirely pelagic; access to reefs is controlled by the local iroij (chief) (Hess, 1999). ...
... Construction projects in Majuro like the airport runway depend on dredging of the reefs to supply materials (Ford, 2015;Richards and Beger, 2011). Islands in the northwest of the atoll are either uninhabited or home to fewer than 100 people, and are therefore less affected by run-off and eutrophication, although these sites are still fished, both for sustenance and the aquarium trade (Pinca et al., 2005). The sites in north Majuro have the highest exposure to wind and waves (with the exception of Maj11, which is inside the lagoon) from the prevailing northeast trade winds. ...
Climate change and human disturbance threatens coral reefs across the Pacific, yet there is little consensus on what characterizes a "healthy" reef. Benthic cover, particularly low coral cover and high macroalgae cover, are often used as an indicator of reef degradation, despite uncertainty about the typical algal community compositions associated with either near-pristine or damaged reefs. In this study, we examine differences in coral and algal community compositions and their response to human disturbance and past heat stress, by analysing 25 sites along a gradient of human disturbance in Majuro and Arno Atolls of the Republic of the Marshall Islands. Our results show that total macroalgae cover indicators of reef degradation may mask the influence of local human disturbance, with different taxa responding to disturbance differently. Identifying macroalgae to a lower taxonomic level (e.g. the genus level) is critical for a more accurate measure of Pacific coral reef health.
... Data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFs) show that unusually high chlorophyll concentrations existed throughout the northwest Hawaiian Islands during the 2004–5 winter as compared with a typical year (Fig. 2). The presence of phytoplankton rich waters was followed by Acanthaster outbreak populations on Johnston Atoll (Brainard et al., 2005), and by sequential outbreaks in the Marshall (Pinca et al., 2005) and Southern Mariana Islands (P. Houk, pers. ...
We hypothesize that the North Pacific transition zone chlorophyll front (TZCF) can episodically deliver enhanced phytoplankton
levels that are linked to the emergence of adult populations of the coral eating starfish Acanthaster planci. In some years, the seasonally migrating TZCF bathes the northwest Hawaiian Islands with chlorophyll-a rich waters during
the winter months that coincide with peak starfish spawning and provide ideal conditions for A. planci larval survival. We found significant relationships between starfish populations in the North Pacific and the southernmost
latitude of the TZCF, chlorophyll-a concentrations, sea surface temperature, and Ekman transport indices since 1967. We propose
that TZCF-triggered primary outbreaks are followed by secondary outbreaks throughout the region, in accordance with the surface
currents and separated by a sequential time lag. Our historical confirmation suggests outbreaks are predictable, which has
immediate coral reef conservation and management consequences.
Preventing the loss of biodiversity is a major challenge in mega-diverse ecosystems such as coral reefs where there is a critical shortage of baseline demographic data. Threatened species assessments play a valuable role in guiding conservation action to manage and mitigate biodiversity loss, but they must be undertaken with precise information at an appropriate spatial scale to provide accurate classifications. Here we explore the regional conservation status of scleractinian corals on isolated Pacific Ocean atolls in the Republic of the Marshall Islands. We compile an integrated regional species list based upon new and historical records, and compare how well the regional threat classifications reflect species level priorities at a global scale. A similar proportion of the 240 species of hard coral recorded in the current survey are classified as Vulnerable at the regional scale as the global scale using the International Union for the Conservation of Nature (IUCN) Red List criteria (23% and 20% respectively), however there are distinct differences in the composition of species. When local abundance data is taken into account, a far greater proportion of the regional diversity (up to 80%) may face an elevated risk of local extinction. These results suggest coral communities on isolated Pacific coral reefs, which are often predicted to be at low risk, are still vulnerable due to the small and fragmented nature of their populations. This reinforces that to adequately protect biodiversity, ongoing threatened species monitoring and the documentation of species-level changes in abundance and distribution is imperative.
