Long‐term associations of common bottlenose dolphins with a fish farm in Hawaiʻi and impacts on other protected species

• Published in: Marine mammal science Vol. 39; no. 3; pp. 794 - 810
• Main Authors: Harnish, Annette E., Baird, Robin W., Corsi, Enrico, Gorgone, Antoinette M., Perrine, Doug, Franco, Alicia, Hankins, Cynthia, Sepeta, Emily
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.07.2023; Wiley Subscription Services, Inc
• Subjects: Aquaculture; Aquatic mammals; behavior; Cetacea; Dolphins; Dolphins & porpoises; Fish; Fish culture; Fish farms; High frequency; interspecific aggression; mariculture; Marine aquaculture; Marine mammals; Network analysis; Pili; Population number; Protected species; Seriola rivoliana; social network; Social networks; Social organization; Stenella longirostris; Tursiops truncatus; Wildlife
• ISSN: 0824-0469; 1748-7692
• DOI: 10.1111/mms.13010

The global expansion of mariculture offers numerous potential benefits but may also pose a threat to wildlife populations. There is currently only one commercial finfish mariculture facility in Hawaiʻi, a nearshore kanpachi (Seriola rivoliana) farm off the west coast of Hawaiʻi Island. This farm lies within the range of several resident odontocete species, and almost daily common bottlenose dolphin (Tursiops truncatus) associations with the farm have been reported since 2007. We analyzed photographs of 35 bottlenose dolphin groups at the farm sighted between 2008 and 2021 in the context of 20 years of survey effort and extensive community science contributions from Hawaiʻi Island. Thirty‐six bottlenose dolphins were identified associated with the farm, representing almost one‐quarter of the estimated total population size. The discovery rate of new individuals at the farm indicates this is a conservative estimate of the total number of individuals associating with the farm, and social network analysis suggests that associations may continue to spread within the population. We also found a high frequency of farm associated bottlenose dolphins showing aggression towards several other species of dolphins, demonstrating impacts to multiple protected species. Hawaiian Nui nā papaha o ka loaʻa ʻana i mau waiwai ma o ka hoʻomōhala honua ʻana i ka hana lawaiʻa, a pēlā nō ka papaha o ka weliweli o nā pūʻuo kai. Hoʻokahi wale nō wahi pāʻoihana lawaiʻa o Hawaiʻi, he loko kāhala (Seriola rivoliana) ma ke kai pāpaʻu ma ke kapakai komohana o ka mokupuni ʻo Hawaiʻi. Aia nō ia loko ma kahi o kekahi mau lāhui naiʻa, a helu ʻia kekahi mau kūkaʻi me nā naiʻa nuku poko (Tursiops truncatus) i kēlā me kēia lā ma ka loko mai ka makahiki 2007. Ua kālailai ʻia he kanakolukūmālima mau kiʻi o nā pūʻulu naiʻa nuku poko i ʻike ʻia ma ka loko mai ka makahiki 2008 a 2021, ma o nā anamanaʻo o iwakālua mau makahiki a me ka hana nui o ke kaiāulu akeakamai o ka mokupuni ʻo Hawaiʻi. Hōʻoia ʻia ka pilina o nā naiʻa nuku poko he kanakolukūmāono me ka loko, he hapahā paha o ka pūʻuo koho huinanui. ʻO kēia ana ʻana i ka ʻike ʻana i mau mea hou ma ka loko, he koho makaʻala i ka huinanui o nā mea e pili ana me ka loko, a wahi a ke ana pilina, e mau ana nō paha kēia ʻano pilina i waena o ka pūʻuo holoʻokoʻa. Ua ʻike pū mākou, ʻoi aʻe ka nui o ka hana mākonā o kēia mau naiʻa pili i ka loko i nā ʻano naiʻa ʻē aʻe ʻaʻohe o lākou pili i ka loko, he hōʻike ia i nā hopena o nā lāhui palekana.