Impacts of pollution, fishing pressure, and reef rugosity on resource fish biomass in West Hawaii

The effect of reef morphology on coral recruitment at multiple spatial scales

Coral reefs are in decline worldwide, making it increasingly important to promote coral recruitment in new or degraded habitat. Coral reef morphology-the structural form of reef substrate-affects many aspects of reef function, yet the effect of reef morphology on coral recruitment is not well understood. We used structure-from-motion photogrammetry and airborne remote sensing to measure reef morphology (rugosity, curvature, slope, and fractal dimension) across a broad continuum of spatial scales and evaluated the effect of morphology on coral recruitment in three broadcast-spawning genera. We also measured the effect of other environmental and biotic factors such as fish density, adult coral cover, hydrodynamic larval import, and depth on coral recruitment. All variables combined explained 72% of coral recruitment in the study region. Coarse reef rugosity and curvature mapped at ≥2 m spatial resolution-such as large colonies, knolls, and boulders-were positively correlated with coral recruitment, explaining 22% of variation in recruitment. Morphology mapped at finer scales (≤32 cm resolution) was not significant. Hydrodynamic larval import was also positively related to coral recruitment in Porites and Montipora spp., and grazer fish density was linked to significantly lower recruitment in all genera. In addition, grazer density, reef morphology, and hydrodynamic import had differential effects on coral genera, reflecting genus-specific life history traits, and model performance was lower in gonochoric species. Overall, coral reef morphology is a key indicator of recruitment potential that can be detected by remote sensing, allowing potential larval sinks to be identified and factored into restoration actions.

Mapping environmental crime to characterize human impacts on islands: an applied and methodological research in Canary Islands

Environmental crimes are a global issue due to the damage they cause to landscapes and ecosystems. This study focused on characterizing environmental crimes in the Canary Islands (Spain). Four categories of environmental crimes related to construction, mining and tilling, solid waste, and liquid waste) were defined and analysed. A total of 28 databases were generated, corresponding to each of the 7 major islands and each environmental crime typology. Each database was linked to information on land use and the socioeconomic and physical characteristics of the territory. For each database, firstly a descriptive statistical analysis was conducted, followed by the generation of a regularized Random Forest model with the aim of identifying characteristics that may be related to the location of environmental crimes. The results showed that, in most cases, proximity to residential accommodations, agricultural areas and industrial zones act as the main explanatory features of the distribution of environmental crimes. Furthermore, a marked pattern of concentration of environmental crimes in the coastal belt of the islands was observed, mainly associated with urban-tourist development since the 1960s and 1970s.

Nutrient thresholds to protect water quality, coral reefs, and nearshore fisheries

A ridge-to-reef framework was developed for 26 watersheds around Guam. Dissolved inorganic nitrogen (DIN) data were collected for one year at the base of streams while coral and fish surveys were conducted on adjacent reefs. Two independent analyses revealed a similar 0.10 mg/l DIN threshold beyond which negative impacts to water quality and coral reefs existed. The influence of DIN was next partitioned with respect to a second primary stressor, fishing pressure. While coral diversity was negatively influenced by DIN, the cover of some stress-tolerant corals increased, such as Porites rus, making coral cover alone a poor indicator of watershed pollution. Less intuitive, DIN predicted increased food-fish biomass that was accounted for by generalist herbivores/detritivores, representing homogenized assemblages, while fishing pressure reduced biomass. Our DIN thresholds resonated with a similar study in American Samoa suggesting broader guidance for water quality legislation may be emerging.

Care, not incarceration: exploring the carcerality of fisheries enforcement and potential decolonial futures in Hawai'i

Current U.S. environmental management paradigms default to enforcement mechanisms that feed into the prison industrial complex, such as fines and jailing. To avoid contributing to and reinforcing mass incarceration and militarism, environmental management systems need to be transformed towards non-carceral forms. Additionally, working towards Indigenous sovereignty and decolonization, requires the strengthening of Indigenous relations with and governance over the land under the respective paradigms of Indigenous communities. This paper uses Hawai'i state fisheries law and programmatic efforts to address a central question: What is the extent and nature of carceral norms within conventional environmental management systems and how do they affect management outcomes? The study examines the current fisheries enforcement scheme in Hawai'i, tracing the embedded logic of carcerality, the degree to which ultimate sources of harm are addressed, and the concentration of governing powers. The results highlight how current fisheries enforcement is insufficient in caring for the seascape and, through its carceral approach, contributes to social injustices, particularly for Kānaka Maoli (Native Hawaiians). Additionally, this paper demonstrates how current efforts in Hawai'i - Community-Based Subsistence Fisheries Areas (CBSFAs), the 'Aha Moku system, and the Makai Watch Program - attempt to empower communities, but ultimately keep enforcement powers centralized within the State, thus perpetuating dependency on the criminal justice system. This study ends with a discussion on how future decarceral environmental governance systems could be designed to center Hawaiian relations & paradigms, particularly by prioritizing the values of re-education, rematriation, and restoration.

The coral conservation crisis: interacting local and global stressors reduce reef resiliency and create challenges for conservation solutions

Coral reefs are one of the most productive and biodiverse ecosystems in the world. Humans rely on these coral reef ecosystems to provide significant ecological and economic resources; however, coral reefs are threatened by numerous local and global anthropogenic factors that cause significant environmental change. The interactions of these local and global human impacts may increase the rate of coral reef degradation. For example, there are many local influences (i.e., sedimentation and submarine groundwater discharge) that may exacerbate coral bleaching and mortality. Therefore, researchers and resource managers cannot limit their narratives and actions to mitigating a sole stressor. With the continued increase in greenhouse gas emissions, management strategies and restoration techniques need to account for the scale at which environmental change occurs. This review aims to outline the various local and global anthropogenic stressors threatening reef resiliency and address the recent disagreements surrounding present-day conservation practices. Unfortunately, there is no one solution to preserve and restore all coral reefs. Each coral reef region is challenged by numerous interactive stressors that affect its ecosystem response, recovery, and services in various ways. This review discusses, while global reef degradation occurs, local solutions should be implemented to efficiently protect the coral reef ecosystem services that are valuable to marine and terrestrial environments.