Winter 1989

https://nsuworks.nova.edu/occ_currents/1057/thumbnail.jp

Investigation of the Kuroshio-coastal current interaction and marine heatwave trends in the coral habitats of Northeastern Taiwan

\ua9 2024 Elsevier B.V.The continually rising concentration of the surface aqueous partial pressure of carbon dioxide has led to sustained ocean acidification and increased sea surface temperature (SST) in the coral habitats of northeastern Taiwan. Since 2016, this region has been experiencing intense marine heatwave (MHW) events, with the accumulated thermal stress reaching its peak between 2020 and 2022. Apart from the attributing factor of the increasing atmospheric carbon dioxide concentration, the Kuroshio (KC) path along the eastern coast of Taiwan has exhibited a westward tendency towards the coast of Taiwan from October to April. The westward and northward components of the KC\u27s branch into the East China Sea (ECS) shelf have rapidly increased. The interplay between the KC and the northeastern Taiwan coastal countercurrent (NETCC) near the coral habitats has formed a counterclockwise circulation, which continues to show a westward trend. This has resulted in the influx of warmer waters into northeastern Taiwan. On another note, the pronounced negative phase of the Pacific decadal oscillation (PDO) and La Ni\uf1a conditions from 2020 to 2022 have further contributed to the increased SST, with the average MHW event accumulating to 172 days annually. The coral bleaching index, degree heating week (DHW), indicates that 2020 was historically the first year for this region to experience a DHW exceeding 8\ub0C-weeks, reaching an Alert Level 2 for bleaching, and 2022 saw even more severe conditions with an average of 12 days at this level. With a reduced number of typhoon incursions in recent years in northeastern Taiwan, and the absence of periodic cold waters to mitigate the heat, the future marine environment of the coral habitats in this region is of significant concern

Detecting Change in Benthic Communities at San Cristobal Reef in La Parguera, Puerto Rico, 2007-2009

The ecological integrity of coral reef ecosystems around the world and their associated goods and services are threatened by the synergistic effects of natural and anthropogenic disturbances. Benthic community composition at San Cristobal reef in La Parguera, Puerto Rico, was monitored from 2007 to 2009 using SCUBA-based photoquadrat surveys, and assessed for change over time using a model-comparison approach, which accounted for spatial autocorrelation. Additionally, the optimal point densities and optimal photoquadrat totals necessary to detect change reliably in proportional cover were investigated. Benthic community structure was similar at all sampling sites throughout the study; algal and sand classes were the dominant classes with non-scleractinian invertebrate classes having similar or greater proportional cover than scleractinian classes. Detected changes in scleractinian classes, including Acropora and Montastraea classes, were lower than detected changes in other invertebrate classes. To investigate optimal sampling intensity, one-hundred re-samples of the point overlays were drawn for ten point densities, ranging from five points quadrat-1 to 90 points quadrat-1, and seven photoquadrat totals, ranging from two photoquadrats to 50 photoquadrats. The change for estimated proportional benthic cover between 2007 and 2008 for four benthic cover classes (M. annularis, P. astreoides, poriferans, and sand) within each re-sample were assessed for change. The minimum number of points required to detect change reliably depended on the cover class and desired detection sensitivity. Low point densities (e.g., five points photoquadrat-1 or 20 points m-2) were sufficient to detect large changes in classes with high proportional benthic cover while high point densities (e.g., 70 points photoquadrat-1 or 280 points m-2) were needed to detect small changes in benthic cover classes with low proportional cover reliably. Intermediate point densities (e.g., 50 points photoquadrat-1 or 200 points m-2) enabled detection of either small changes in classes with high proportional cover or large changes in classes with low proportional cover. Lower quadrat totals (e.g., 20 photoquadrats 100 m-2) were sufficient to detect large changes, and higher quadrat totals (e.g., 40 photoquadrats 100 m-2) were necessary to detect small changes reliably. Therefore, researchers should be conservative when determining sampling intensity and select higher point densities (e.g., 50-70 points photoqradrat-1) and higher photoquadrat totals because a less intense sampling regime (e.g., five points photoquadrat-1 or 20 photoquadrats) could result in inaccurate proportional cover estimates and unreliable detection of change. Programs monitoring benthic community structure in coral reefs using points overlaid on photoquadrats should determine the appropriate point density and number of photoquadrats per unit area based on proportional cover of the benthic classes, minimum change in cover to be detected, and the spatial autocorrelation distance, and should account for spatial autocorrelation between points when performing statistical analyses

Global coral bleaching event detection from satellite monitoring of extreme heat stress

Over the past four decades, coral bleaching events have occurred with increasing frequency and severity, directly linked to increasing ocean temperature due to climate change. For the latter half of that period, satellite monitoring by NOAA Coral Reef Watch in near real-time has provided invaluable insight into bleaching risk. Here, we describe a novel application of those products to develop basin-scale tools for tracking the development of extreme heat events that enable monitoring of global coral bleaching events. Case studies of historical extreme events (1982-2018) across the three tropical ocean basins (Indian, Pacific and Atlantic) were analysed using this basin-scale approach to identify key thresholds of heat stress extent for the definition of global bleaching. Global-scale events are apparent when all three tropical basins experience heat stress in at least 10% of reef-containing locations. An 8-month ‘detection window’ was determined as the optimal period of time through which pixels exposed to heat stress should continue to be counted as part of a basin-scale event to account for seasonal variations across ocean basins. Understanding the broader context of basin-scale conditions can inform management of individual reefs, management networks and other reef stakeholders. Operationalising this product for near real-time delivery will provide an effective communication of the status of coral reefs around the world during an era of unprecedented climate threats

Conservation science in NOAA’s National Marine Sanctuaries: description and recent accomplishments

This report describes cases relating to the management of national marine sanctuaries in which certain scientific information was required so managers could make decisions that effectively protected trust resources. The cases presented represent only a fraction of difficult issues that marine sanctuary managers deal with daily. They include, among others, problems related to wildlife disturbance, vessel routing, marine reserve placement, watershed management, oil spill response, and habitat restoration. Scientific approaches to address these problems vary significantly, and include literature surveys, data mining, field studies (monitoring, mapping, observations, and measurement), geospatial and biogeographic analysis, and modeling. In most cases there is also an element of expert consultation and collaboration among multiple partners, agencies with resource protection responsibilities, and other users and stakeholders. The resulting management responses may involve direct intervention (e.g., for spill response or habitat restoration issues), proposal of boundary alternatives for marine sanctuaries or reserves, changes in agency policy or regulations, making recommendations to other agencies with resource protection responsibilities, proposing changes to international or domestic shipping rules, or development of new education or outreach programs. (PDF contains 37 pages.

NOAA FY 2000 Budget Request

This report provides an overview of NOAA, including agency-wide information, a detailed description of the President's FY 2000 Budget Submission to the Congress, and a discussion of the NOAA Strategic Plan

Modeling seabird group size: implications for ecological impact assessments

The purpose of this project is to model seabird flock size data to provide recommendations to the Bureau of Ocean and Energy Management for offshore wind turbine placement. Our hypothesis is that ecological characteristics influence which statistical distribution will provide the best fit to seabird flock size data. To test this, seabird species can be grouped based on shared ecological traits, such as foraging mechanism or diet

Evaluating Satellite-Based Sea Surface Temperatures, \u3ci\u3eIn Situ\u3c/i\u3e Observations, and Coral Symbioses in Southwestern Puerto Rico

I examined the effects of in situ and satellite-based sea surface temperatures (SST) on the seasonal coral-algae symbiotic relationship in La Parguera, Puerto Rico. Climate change-driven rising sea temperatures are endangering most of the world’s reefs, which are currently in decline. Satellite remote sensing datasets support global-scale characterization and monitoring of risks to reefs associated with increasing temperatures. Corals’ unique symbiotic relationship with unicellular algae in the family Symbiodiniaceae is largely responsible for helping corals cope with increasing ocean temperatures, and some corals are able to adjust their symbiont species in response to temperature disturbances. My research had two components to evaluate how satellite SST and in situ data corresponded to symbiont shuffling: (1) assessment of in situ temperatures at the depth of coral reefs with corresponding satellite-based SST datasets, and (2) evaluating the seasonal coral symbioses community dynamics of Orbicella faveolata and Montastraea cavernosa using high resolution quantitative PCR. This study involved a combination of fieldwork, computational analysis, and detailed laboratory work. All three satellite-based SST datasets evaluated produced a cool bias and represented the temperature at the depth of the corals with ~1°C offset. There were no seasonal differences in the coral symbioses for either species. The results highlight the need for further in situ and satellite validation studies, and the complexity of the coral symbiotic relationship. The conclusions will be useful to coral conservation managers interested in using satellite SST datasets to monitor coral reefs, and marine bioengineering efforts focused on optimizing the coral symbioses to combat climate change

Oceanus.

v. 34, no. 1 (1991