Microplastics (MP), the debris that collectively refers to plastic fragments and particles of <5 mm in size within marine environments, has been the subject of interest within the past decade. Evidence of its occurrence and abundance, has been recorded in this communication after examining gastrointestinal specimens of eight commercially available fish species common to the Arabian (Persian) Gulf acquired locally from the State of Kuwait. The species studied belonged to different trophic levels, and the specimens were subjected to Micro Raman and Micro Fourier Infrared Spectroscopy (FTIR) in Attenuated Reflective Mode (ATR) to determine the presence and type of polymer of the MP. The detected MP set a president for the first time in the examined fish species within the State of Kuwait, which are of immense commercial importance. Various particles were detected, and three MP particles (fragments) were detected within the guts of Acanthopagrus latus, Eleutheronemaa tetradactylum and Lutjanus quinquelineatus. Based on the nature and behaviour of these particular fish types which prefer to stay in muddy waters and sheltered lagoons, it is suspected that common primary sources of MP (i.e. waste fragmentation) have led to passive/active intake (e.g. detritus ingestion) of these particles (fragments) by these species of fish in Kuwait.

Bilateral asymmetry is presumed to reveal the developmental variability of the fish in polluted aquatic environments. In these habitats, high-level asymmetry develops, and these fish expend more energy to balance their growth than fish that are not under an impact. A total of 210 specimens of Acanthopagrus bifasciatus, A. latus and Sparidentex hasta were collected from the marine waters of Iraq in the northwest part of the Arabian Gulf. The asymmetry was calculated for the sagittal otolith characters of length and width. Otolith width has lower asymmetry than otolith length for the three sparid fish species investigated. An increase in the value of fluctuating asymmetry with fish length was observed. This could be a pertinent indicator of pollution in the habitat.

The Gippsland Lakes estuary, a Ramsar listed wetland, in Victoria, Australia, is an area of potential concern for metal pollution due to influxes of human population and associated anthropogenic activities. A biomonitoring exercise was undertaken where the concentrations of 9 metals (Cr, Fe, Cu, Zn, As, Se, Ag, Cd and Hg) were analysed in the soft tissue of two common sessile invertebrates: the mussel Mytilus edulis and the barnacle Amphibalanus variegatus from 6 locations on two different occasions throughout the Gippsland Lakes estuary. A salinity gradient exists in the Lakes, from seawater at Lakes Entrance in the east, decreasing down to < 10 PSU in the west at Lake Wellington during times of rainfall, which is a major factor governing the growth and distribution of both species. Dissolved metal levels in general were low; however, Cu at most sites exceeded the 90% trigger values, while all Zn concentrations exceeded the lowest 80% trigger values of the ANZECC marine water quality guidelines for environmental health. Elevated levels of Cu and Zn were found particularly in barnacles at some sites with environmental contamination due to leaching from anti fouling paints and sacrificial zinc anodes. Elevated levels of Ag and Cd were found in mussels at the Hollands Landing site, which is immediately adjacent to a boat ramp, and Cd and Ag at this site are suspected to originate from inland anthropogenic sources. Concentrations of As in M. edulis across all 6 sites in both sampling periods had mean wet weight As concentrations exceeding the maximum level stated in the FSANZ guidelines. A. variegatus contained elevated levels of Hg especially at the North Arm site with a maximum of 13.6 μg Hg/g dry wt., while A. variegatus also showed temporal changes in Hg concentrations across sites. The maximum Hg concentration found in Mytilus edulis was 1.49 μg Hg/g dry wt. at the Hollands Landing site. Previous contaminant studies of biota in the Lakes have targeted sampling of singular predatory or migratory species, such as Black Bream (Acanthopagrus butcheri) and the Burrunan dolphin (Tursiops australis). This is the first biomonitoring study conducted on sessile organisms to assess metal contamination in the system.