Editing Gray whale (section)

==Threats==
According to the Government of Canada's Management Plan for gray whales, threats to the eastern North Pacific population of gray whales include:<ref>[http://www.dfo-mpo.gc.ca/species-especes/species-especes/greyWhale-NP-baleine-grise-PN-eng.htm The Grey Whale (Eastern North Pacific Population)] {{webarchive |url=https://web.archive.org/web/20160114181406/http://www.dfo-mpo.gc.ca/species-especes/species-especes/greyWhale-NP-baleine-grise-PN-eng.htm |date=January 14, 2016 }}. Species at Risk. dfo-mpo.gc.ca</ref> increased human activities in their breeding lagoons in Mexico, [[climate change]], [[marine mammals and sonar|acute noise]], toxic spills, aboriginal whaling, [[bycatch|entanglement]] with fishing gear, boat collisions, and possible impacts from fossil fuel exploration and extraction.

Western gray whales are facing large-scale offshore oil and gas development programs near their summer feeding grounds, as well as fatal net entrapments off Japan during migration, which pose significant threats to the future survival of the population.<ref name="iwcoffice.org"/> The substantial nearshore industrialization and shipping congestion throughout the migratory corridors of the western gray whale population represent potential threats by increasing the likelihood of exposure to ship strikes, chemical pollution, and general disturbance.<ref name="IUCN Western"/><ref name="Weller, D. et al 2002"/>

Offshore gas and oil development in the Okhotsk Sea within {{convert|20|km|mi|abbr=on}} of the primary feeding ground off [[Sakhalin-II#Plans for Piltun-Astokhskoye-C platform|northeast Sakhalin Island]] is of particular concern. Activities related to oil and gas exploration, including geophysical seismic surveying, pipelaying and drilling operations, increased vessel traffic, and oil spills, all pose potential threats to western gray whales. Disturbance from underwater industrial noise may displace whales from critical feeding habitat. Physical habitat damage from drilling and dredging operations, combined with possible impacts of oil and chemical spills on benthic prey communities also warrants concern. The western gray whale population is considered to be endangered according to IUCN standards.<ref name="IUCN Western"/><ref name=Reeves/>

Along Japanese coasts, four females including a cow-calf pair were trapped and killed in nets in the 2000s. There had been a record of dead whale thought to be harpooned by dolphin-hunters found on [[Hokkaido]] in the 1990s.<ref name="IUCN Western"/><ref>{{cite web|author=Yamada T.|author2=Watanabe Y.|title=Marine Mammals Stranding DataBase – Gray Whale|url=http://svrsh2.kahaku.go.jp/drift/FMPro?-db=rec2000web.fp5&-lay=hp&-format=/drift/e/detail.htm&rec_id=19960516M-088&-find|publisher=The [[National Museum of Nature and Science]]|access-date=2015-01-13|url-status=dead|archive-url=https://web.archive.org/web/20140512215922/http://svrsh2.kahaku.go.jp/drift/FMPro?-db=rec2000web.fp5&-lay=hp&-format=%2Fdrift%2Fe%2Fdetail.htm&rec_id=19960516M-088&-find|archive-date=2014-05-12}}</ref> Meats for sale were also discovered in Japanese markets as well.<ref>{{cite journal|doi=10.1111/j.1748-7692.2002.tb01036.x|title=Gray Whale Products Sold in Commercial Markets Along the Pacific Coast of Japan|journal=Marine Mammal Science|volume=18|page=295|year=2002|last1=Baker|first1=C. S.|last2=Dalebout|first2=M. L.|last3=Lento|first3=G. M.|last4=Funahashi|first4=Naoko|issue=1 |bibcode=2002MMamS..18..295B }}</ref>

2019 has had a record number of gray whale strandings and deaths, with 122 strandings in United States waters and 214 in Canadian waters. The cause of death in some specimens appears to be related to poor nutritional condition.<ref>{{Cite web |last= |first= |date=2024-11-04 |title=2019-2023 Eastern North Pacific Gray Whale UME (CLOSED) {{!}} NOAA Fisheries |url=https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-eastern-north-pacific-gray-whale-ume-closed |access-date=2024-11-22 |website=NOAA |language=en}}</ref> It is hypothesized that some of these strandings are related to changes in prey abundance or quality in the Arctic feeding grounds, resulting in poor feeding. Some scientists suggest that the lack of sea ice has been preventing the fertilization of amphipods, a main source of food for gray whales, so that they have been hunting krill instead, which is far less nutritious. More research needs to be conducted to understand this issue.<ref>{{Cite web |last=Daley |first=Jason |title=NOAA Is Investigating 70 Gray Whale Deaths Along the West Coast |url=https://www.smithsonianmag.com/smart-news/noaa-investigating-dozens-gray-whale-deaths-along-west-coast-180972333/ |access-date=2024-11-22 |website=Smithsonian Magazine |language=en}}</ref>

A recent study provides some evidence that solar activity is correlated to gray whale strandings. When there was a high prevalence of sunspots, gray whales were five times more likely to strand. A possible explanation for this phenomenon is that solar storms release a large amount of electromagnetic radiation, which disrupts Earth's magnetic field and/or the whale's ability to analyze it.<ref>{{Cite web |last=Hickok |first=Kimberly |date=2020-01-10 |title=Solar Storms Might Be Causing Gray Whales to Get Lost |url=https://www.livescience.com/solar-storms-and-gray-whale-strandings.html |access-date=2024-11-22 |website=livescience.com |language=en}}</ref> This may apply to the other species of cetaceans, such as sperm whales.<ref>{{cite journal |last1=Vanselow |first1=Klaus Heinrich |last2=Jacobsen |first2=Sven |last3=Hall |first3=Chris |last4=Garthe |first4=Stefan |title=Solar storms may trigger sperm whale strandings: explanation approaches for multiple strandings in the North Sea in 2016 |journal=International Journal of Astrobiology |date=15 August 2017 |volume=17 |issue=4 |pages=336–344 |doi=10.1017/s147355041700026x |doi-access=free |hdl=10037/24936 |hdl-access=free }}</ref> However, there is not enough evidence to suggest that whales navigate through the use of magnetoreception (an organism's ability to sense a magnetic field).

Orcas are "a prime predator of gray whale calves."<ref name="BANG">{{cite news| title=Unusual Number of Killer Whales Sighted |page=B1 |author=Andrew Lachman |publisher=Bay Area News Group | work=San Jose Mercury-News |date=May 8, 2018}}</ref> Typically three to four orcas ram a calf from beneath in order to separate it from its mother, who defends it. Humpback whales have been observed defending gray whale calves from orcas.<ref name="BANG" /> Orcas will often arrive in Monterey Bay to intercept gray whales during their northbound migration, targeting females migrating with newborn calves. They will separate the calf from the mother and hold the calf under water to drown it. The tactic of holding whales under water to drown them is certainly used by orcas on adult gray whales as well.<ref>{{cite web| url = https://www.youtube.com/watch?v=TmO0wiK5DqI| title = Deadly Killer Whale Moments (BBC Earth)| website = [[YouTube]]}}</ref> It is roughly estimated that 33% of the gray whales born in a given year might be killed by predation.<ref>{{cite journal |last1=Morell |first1=V. |title=Killer Whales Earn Their Name |journal=Science |date=20 January 2011 |volume=331 |issue=6015 |pages=274–276 |doi=10.1126/science.331.6015.274 |pmid=21252323 |bibcode=2011Sci...331..274M }}</ref>