Marine mammal records from Iran

Abstract

Iran has 1,700km of coastline that borders the Persian Gulf and the Arabian Sea in the northwest Indian Ocean. Apart from a handful of records, almost nothing is known about which marine mammal species occur in Iranian waters. This review was conducted to fill this information gap. A total of 127 marine mammal records of 14 species were compiled from Iranian coastal waters. Ninety-nine were from the Persian Gulf, 26 from the Gulf of Oman and 2 were of unknown location. Records of finless porpoise (Neophocaena phocaenoides) (25), Indo-Pacific humpback dolphin (Sousa chinensis) (24) and Indo-Pacific bottlenose dolphin (Tursiops aduncus) (22) were by far the most numerous, a probable reflection of their inshore distribution and local abundance. Other species recorded were long-beaked common dolphin (Delphinus capensis tropicalis), roughtoothed dolphin (Steno bredanensis), striped dolphin (Stenella coeruleoalba), spinner dolphin (Stenella longirostris), Risso’s dolphin (Grampus griseus), false killer whale (Pseudorca crassidens), sperm whale (Physeter macrocephalus) and dugong (Dugong dugon). Records of 26 mysticetes were compiled, 10 of which were tentatively identified as Bryde’s whales (Balaenoptera edeni), 1 possible fin whale (Balaenoptera physalus), 3 humpback whales (Megaptera novaeangliae) and the remainder were not identified to species. The largest threat to small cetaceans in Iran is likely to be incidental capture in fishing gear. Nine finless porpoises were recorded as bycatch and this and other coastal species may be declining due to unsustainable mortality rates. Some of the world’s busiest shipping lanes pass through Iranian waters and ship strikes are likely to be the largest threat to mysticetes in the area.

Report of the Scientific Committee

“…In Iran, a compilation of marine mammal records from universities, natural history museums, Department of Environment (DoE) offices, Iranian Fisheries Research Organisation (IFRO) centres and various non-governmental wildlife organisations (NGOs) confirmed 25 records of finless porpoise; 23 were from the Persian Gulf and two from the Gulf of Oman (Braulik et al, 2010). Records appear to be concentrated around Bushehr, near the head of the Arabian/Persian Gulf, and Qeshm Island, near the Strait of Hormuz.…”

“…In Taiwan, an analysis of strandings between 2019-20, indicated that of the known causes of death, bycatch accounted the highest proportion or mortality, followed by ship strike and disease (IWC, 2021c). In Kuwait, where cause of death was determined, ship strike accounted for the highest proportion, followed by bycatch of recovered finless porpoise strandings (Nithyanandan and Bohadi, 2021) and in Iran, the high number of bycaught individuals recorded suggests that incidental mortality in fishing gear is unsustainable (Braulik et al, 2010). There is little information on the level of directed take, however, it seems unlikely that this is a significant threat, compared to bycatch.…”

After two decades: extremely rare records of dugongs, Dugong dugon (Sirenia: Dugongidae), in the Iranian Persian Gulf

“…Conversely, the Iranian coast of the Persian Gulf is thought not to be inhabited by dugongs (Preen, 2004;Braulik et al, 2010). This may be because seagrasses (Order Alismatales), which dugongs exclusively depend on for food (Jefferson et al, 2008), are not distributed uniformly across the sea (Erftemeijer and Shuail, 2012).…”

“…It raises the suspicion that perhaps some of the sightings may have been opportunistic, made by non-scientists, and could have confused the Indo-Pacific finless porpoise, Neophocaena phocaenoides (G. Cuvier), common in HBR, with D. dugon. Neophocaena phocaenoides is widely distributed in the Persian Gulf, including in the shallow Iranian waters (Baldwin et al, 1999;Braulik et al, 2010), and due to their gray color and lack of dorsal fin, are most likely to be confused with D. dugon where their habitats overlap in shallow tropical Indo-Pacific waters (Jefferson et al, 2008).…”

Sourcing aliphatic and polycyclic aromatic hydrocarbons (PAHs) in Jinga shrimp (Metapenaeus affinis) muscle tissues and surface sediments (study case: Northwest Persian Gulf)

“…have been exposed to multiple environmental stressors. Oil spills from the discharge processes, tanker water depletion, oil well operations, tanker accidents, destruction, and burning of oil rigs and urban runoffs have imposed the Persian Gulf to severe environmental hazards (Nadim et al, 2008;Braulik et al, 2010). Due to the rapid industrial growth in the region and high-density oil facilities as well as the high volume of oil shipments, the risk of oil pollution in this area has signi cantly increased, becoming one of the most anthropogenically impacted regions in the world (Neff., 1979;Mehdinia et al, 2015;Vaughan et al, 2019;Dashtbozorg., 2019).…”