This report is part of the Technical Report Series resulting from the Winter 2006 Oceanographic Cruise conducted by the Regional Organization for the Protection of the Marine Environment (ROPME). The cruise aimed to enhance scientific understanding of the status of the marine environment within the ROPME Sea Area (RSA) through the investigation of a wide range of physical, chemical, and biological parameters.
The report presents the findings of the study on macrobenthic communities, which are organisms living within or on marine sediments. These organisms are considered important biological indicators for assessing the health of marine ecosystems due to their role in organic matter and nutrient cycling, as well as their close relationship with sediment quality and environmental pressures.
The report was prepared by the Center for Environment and Water – Research Institute, King Fahd University of Petroleum and Minerals (KFUPM), under the supervision of a scientific team led by Dr. Abdulaziz Al-Suwailem, as part of regional scientific cooperation efforts supporting environmental monitoring and assessment programmes in the ROPME Sea Area.
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Study Objectives and Methodology
The study aimed to assess:
* The taxonomic composition of macrobenthic communities.
* Their abundance and spatial distribution within the ROPME Sea Area.
* Levels of biodiversity and species dominance.
* The relationship between benthic communities and environmental characteristics of water and sediments.
* The potential use of biological indicators, such as the polychaete/amphipod ratio, to assess the impacts of oil pollution and environmental stress.
Benthic sediment samples were collected during the period from February to March 2006 from 51 stations distributed along 21 transects, with sampling depths ranging from 13 to 104 metres. The survey covered different areas of the ROPME Sea Area, including the northern and southern inner regions and the Sea of Oman.
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Major Findings
Taxonomic Diversity of Macrobenthos
The study recorded 202 species of macrobenthic organisms belonging to:
141 genera
100 taxonomic families
Polychaete worms were the most dominant group, representing approximately 52% of the total recorded organisms, followed by crustaceans (27%) and mollusks (13%).
The dominant species recorded included:
*Ampelisca brevicornis (Crustacea).
*Prionospio sp. (Polychaeta).
*Eurythoe sp. (Polychaeta).
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Abundance and Distribution of Benthic Communities
The abundance of macrobenthic organisms ranged between:
60 individuals/m² and 1,530 individuals/m², with an average abundance of approximately 425 individuals/m².
The highest densities were recorded in the **Sea of Oman**, mainly due to increased abundance of polychaetes and crustaceans. Meanwhile, the northern inner part of the ROPME Sea Area exhibited high species diversity, attributed to habitat variability and differences in sediment characteristics.
The results also demonstrated variations in benthic distribution according to sediment type. Higher abundance was generally recorded in sandy environments, while higher species diversity was mostly associated with muddy sediments.
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Biodiversity Status and Environmental Health
Biodiversity indicators revealed that most surveyed stations supported stable and healthy benthic communities, with the following observations:
* Approximately 75% of the stations recorded high diversity values, indicating healthy macrobenthic communities.
* Species dominance levels were generally low, indicating the absence of excessive dominance by particular species within the ecosystem.
* Community structure analyses showed no significant differences among the three main study regions, except for variations related to sediment characteristics.
Furthermore, analyses using biological indicators related to oil pollution showed that all surveyed stations recorded values indicating no clear evidence of oil pollution impacts on benthic communities during the study period.
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Relationship Between Macrobenthos and Environmental Factors
The study examined the relationship between macrobenthic distribution and several environmental parameters, including:
* Temperature.
* Salinity.
* Dissolved oxygen.
* Sediment characteristics.
* Organic matter content.
* Selected heavy metals and organic pollutants.
The results demonstrated that sediment characteristics, particularly grain size and sediment composition, play a significant role in determining the distribution of benthic communities. Certain chemical parameters, including heavy metals and polycyclic aromatic hydrocarbons (PAHs), also showed influence on benthic distribution patterns.
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Importance of the Study
This report represents an important scientific reference for understanding the status of benthic biodiversity within the ROPME Sea Area and provides a valuable baseline for:
* Assessing future changes in the health of marine ecosystems.
* Supporting regional marine environmental monitoring programmes.
* Identifying the impacts of human activities and pollution on benthic habitats.
* Promoting sustainable management of shared marine resources among Member States.
The findings confirm that macrobenthic communities in the ROPME Sea Area during the Winter 2006 survey demonstrated a good level of stability and biodiversity. However, continued long-term monitoring programmes remain essential to detect and assess any potential future environmental changes.
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Regional Organization for the Protection of the Marine Environment (ROPME)
Enhancing scientific knowledge and protecting the marine environment of the shared regional sea area.
