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Research field: Marine Ecology, Blue Carbon, Stable Isotopes
Expert: S.M. Hosseini
Phone: 01144998155
Address:
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Ribbonfish, Trichiurus lepturus (Linnaeus, 1758), is an important component of subsistence fisheries throughout its tropical and subtropical distribution. The catch rate of ribbonfish has increased seven-fold in a decade in the Persian Gulf and Oman Sea. We collected monthly biological samples from T. lepturus, to estimate growth and mortality parameters, and identify species reproductive pattern. The annual instantaneous rate of fishing mortality (0.63 year-1) was higher than the target (Fopt= 0.26 year− 1) and limit (Flim= 0.35 year− 1) reference points, indicating that the ribbonfish stock is overexploited. The gonado-somatic index and monthly gonadal maturity stages of harvested fishes indicated that T. lepturus presents continuous
Biological trait analysis has been successfully used to describe ecological functions in marine benthic ecosystems. However, it has rarely been applied to mangrove habitats. This study analyzes taxonomic and functional diversity and the components thereof in two mangrove habitats in the Hara Biosphere Reserve, Persian Gulf: a vegetated area with both mangrove trees and pneumatophores, and an adjacent mudflat. Species diversity and functional diversity were higher in vegetated habitats and slightly increased in summer. Our study demonstrates the importance of mangrove structural complexity for the structure and functioning of invertebrate communities. The macrofaunal communities were characterized by low diversity and a high dominance of jus
An Ecopath ecosystem modeling was applied to describe the trophic model of coastal fisheries ecosystem of the northern Persian Gulf. A total of 32 functional groups and species were used to determine the key features of the aquatic system. We also examined the stability and developmental stage of the Persian Gulf ecosystem. Total primary production/total respiration was calculated to be> 1 indicating that more energy is produced than respired within the system. Indicators of ecosystem stability and development were estimated as follows: ominivory index= 0.29; connectance index= 0.14; Path length= 1.005; relative low biomass to throughput ratio= 0.0008; ascendency= 12.26; Finn’s cycling index= 2.01; high primary production to biomass ratio
Length–weight and length–length relationships have important implications for the life history patterns of fish species (Moutopoulos and Stergiou 2002; Froese, 2006). Such data are essential to understanding morphological comparisons among species and populations (Safran, 1992; Moutopoulos and Stergiou 2002; Froese et al., 2011), and are highly significant for fisheries research, management, and conservation (Christensen and Walters, 2004). The present study establishes the LWRs of rare fish species (ie, jumping halfbeak, Hemiramphus archipelagicus, diamondback puffer, Lagocephalus guentheri and short-nosed tripod, Triacanthus biaculeatus) for which a little information is available in the region. The reported data for round spadefish,
This study was conducted to determine the temporal and spatial distribution of Opusia indica in the Hara Biosphere Reserve in the Persian Gulf. Seasonal sampling (four seasons) was performed from winter 2019 to autumn 2019. Sampling was done in five regions and three habitats within each region using metal quadrats with dimensions of 25? 25 cm. In each habitat, environmental parameters including temperature, salinity, dissolved oxygen, pH along with organic matter and grain size were measured. The results showed that the abundance and biomass of Opusia indica have decreasing trend with increasing habitat complexity. Seasonally, the highest abundance and biomass were observed in winter and autumn, respectively, and the lowest abundance and b
Macrofauna play a key role in the functioning of mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of macrofaunal communities across different habitats in the mangrove forests of the Persian Gulf is limited. In this study, we investigated species diversity and biological trait patterns of macrofauna in different mangrove-associated habitats, i.e. encompassing actual mangrove forests, and adjacent Beaches and Creeks, which exhibit different levels of habitat heterogeneity. Samples were collected from the different habitats in five different locations, over four seasons. A total of 122 macrofauna taxa were identified. The diversity of species was higher in summer than in winter. In the Beach habita
The functioning of ecosystems is decisively dependent on the composition and distribution of the functional traits of the constituent species. We used trait analysis to represent aspects of marine benthic functioning, using a 20-year time-series (1992–2011) on macrozoobenthos collected annually at four monitoring sites in the southern North Sea. Temporal patterns of trait composition and taxonomic composition were compared to test whether they exhibited similar or contrasting responses to environmental change. Temporal changes in trait composition were more similar among monitoring sites than the changes in the taxonomic composition suggesting that trait compositions converge towards a common structure sculpted by common environmental dri
The length-weight and some length- length relationships of six fish species, including Lutjanus malabaricus, Acanthopagrus latus, L. johnii, Rastrelliger kanagurta, Gerres longirostris and Sillago sihama from the Persian Gulf were studied. The specimens were collected?from?landing centers and their morphometics, including total length (TL), fork length (FL), standard length (SL), body depth (BD), and caudal fin height (FH) measured to?the nearest?mm and weighed to the nearest 0.1 g. All?length-weight?relationships?were significant, with the coefficient of determination (r2) ranging from 0.84 (G. longirostris) to 0.98 (L. malabaricus) (P<0.01). The parameter?b?ranged from 2.54 (R. Kanagurta) to 2.98 (S. sihama). The results indicated isometr
The current study aimed to determine the isotopic composition of different food sources and their contribution to the diet of Parasesarma persicum inhibiting a mangrove ecosystem in the Persian Gulf. The potential food sources, ie, Avicennia marina green and yellow leaves, Particulate Organic Matter (POM), Microphytobenthos (MPB), and Sediment Organic Matter (SOM) were collected for stable isotope analysis. The most 13 C-depleted values were observed for mangroves with mean δ 13 C values of-28.31‰ and-28.05‰ for green and yellow leaves, respectively. The mean δ 15 N values of mangrove leaves were 3.79‰ and 5.08‰ for green and yellow leaves, respectively. The crab P. persicum had an average value of carbon and nitrogen isotopes of-
We assessed the macrozoobenthos community structure, biodiversity, and health status within Hara Biosphere Reserve mangrove ecosystem in the Bandar-e Khamir and Qeshm Island. Samples were collected from eight stations within two habitats, including pneumatophore zones (vegetated) and creek bank. Sampling conducted in January and February 2018. In total, 27 taxa belonging to 19 families were identified. The results showed that Opusia indica, Ctenodrilus sp. and Perinereis horsti were the most abundant species in Hara Biosphere Reserve. No significant differences were observed in the Shannon-Wiener biodiversity index between two regions (P= 0.53) and also habitats (P= 0.68). Multidimensional scaling plots were used to identify differences in