Projected habitat preferences of commercial fish under different scenarios of climate change.

The challenges of commercial species with the threats of climate change make it necessary to predict the changes in the distributional shifts and habitat preferences of the species under possible future scenarios. We aim to demonstrate how future climatic changes will affect the habitat suitability of three species of commercial fish using the predictive technique MaxEnt. The dataset used to extract geographical records included OBIS (54%), GBIF (1%), and literature (45%). The output of the model indicated accurate projections of MaxEnt (AUC above 0.9). Temperature was the main descriptor responsible for the main effects on the distribution of commercial fish. With increasing RCP from 2.5 to 8.5, the species would prefer saltier, higher temperatures and deeper waters in the future. We observed different percentages of suitable habitats between species during RCPs showing distinct sensitivity of each fish in facing climate changes. Negative effects from climate change on the distribution patterns of commercial fish were predicted to lead to varying degrees of reduction and changes of suitable habitats and movement of species towards higher latitudes. The finding emphasizes to implement adaptive management measures to preserve the stocks of these commercial fish considering that the intensification of the effects of climate change on subtropical areas and overexploited species is predicted.

Algal blooms historical outbreaks in the northern coastal waters of the Persian Gulf and Oman Sea (1980-2015).

Harmful algal blooms (HABs) have been serious environmental problems in the Persian Gulf and Oman Sea in recent years. There has been an increase in occurrence of HABs in coastal waters of Hormuzgan Province (to the north of the Persian Gulf and Oman Sea) in recent decade, due to eutrophication as a result of human activities. In this review, HAB phenomena in coastal waters of Hormuzgan Province are summarized, including, causative species, timing and the location of blooms during a 35-year time span from 1980 to 2015. This review illustrates that 436 algal blooms have been recorded in the north of the Persian Gulf, formed by 17 species of phytoplankton; 270 of harmful dinoflagellate (Margalefidinium polykrikoides) blooms have led to huge catastrophic impacts on the economy, environment, and society. In addition, most algal blooms (49%) have occurred in the coasts of Bandar Abbas. The data in this review suggest supporting the establishment of an algal bloom monitoring and control program in the coastal waters of the northern part of the Persian Gulf and Oman Sea (Hormuzgan Province).

Occurrence, abundance and characteristics of microplastics in some commercial fish of northern coasts of the Persian Gulf.

This study assessed the abundance of microplastics (MPs) in muscle, liver, gill, and gastrointestinal tissues of 14 fish species from the Persian Gulf. The quality control showed no significant difference in MPs abundance between blank samples and muscle and liver tissues. The mean abundance of MPs accumulated in gill and gut was 2.85 ± 1.57 and 2.46 ± 1.46 pa/individual, respectively. The maximum mean abundance of MPs was observed in the gill (5.71 pa/ind) of the fish Thunnus tonggol and gut tissue (5.67 pa/ind) of the fish Sphyraena putnamiae. Fiber, black color and size of 23-75 µm were the predominant form of MPs. There was a significant positive correlation between the total fish length and the abundance of MPs. MPs were more abundant in pelagic fish (5.79 ± 5.98) than demersal fish species (3.89 ± 3.53). The level of fish contamination with MPs was low to moderate in comparison to the ranges reported in the literature.

Bisphenol A (BPA) and polycyclic aromatic hydrocarbons (PAHs) in the surface sediment and bivalves from Hormozgan Province coastline in the Northern Persian Gulf: A focus on source apportionment.

This study investigates Polycyclic Aromatic Hydrocarbons (PAHs) and Bisphenol-A (BPA) pollution in coastal sediments and bivalves of Hormozgan Province coastline. The results indicated that the BPA concentration in some bivalves reached up to 340.16 ng g-1. The mean BPA concentration in the sediment samples was also 787.01 ng g-1. The ∑PAHs content in sediments ranged from 14.54 to 85.00 ng g-1, while values for bivalves ranged from 5.37 to 16.40 ng g-1. Individual PAH concentrations in sediments exceeded those in bivalves for which only LMW PAHs were detected. A combination of techniques including Self-Organizing Maps (SOM), Positive Matrix Factorization (PMF), and Cluster Analysis (CA) were applied and both petrogenic and pyrogenic sources were identified. The risk of PAHs in the sediments was relatively low according to the sediment quality guidelines. The health risk indices suggest that exposure to PAHs through bivalve consumption does not impose harmful health effects upon consumers.

Total petroleum hydrocarbons in sediments from the coastline and mangroves of the northern Persian Gulf.

To provide baseline information for the marine ecosystem of Hormozgan province, the distribution of petroleum hydrocarbons was evaluated in 52 stations involved in the mangrove and coastline ecosystem. Coastline sampling sites included areas facing harbor, river, domestic and industrial discharge. Sediment samples were analyzed based on ultraviolet fluorescence spectroscopy. Petroleum hydrocarbons showed narrow variations ranging from non-detectable (ND) to 1.71 and from 0.2 to 0.63µg/g dry weight for coastline and mangrove sediments, respectively. The detected concentrations for total petroleum hydrocarbons were lower than guideline values for ecological risk. Furthermore, the minimum environmental risk was confirmed by background levels for the Persian Gulf, the Sea of Oman, and detected values for reference areas. The results were regarded as background data in the studied area, and, considering the rapid expansion of activities related to the petroleum industry in Hormozgan province, the continuous monitoring of pollutants is recommended.