Editing Sea lion (section)

=== Parasites and diseases ===
Galapagos sea lions (''Zalophus wollebaeki'') can be infected with ''Philophthalmus zalophi'', an eye fluke. These infections have heavy impacts on the survival of juveniles.<ref name="Web of Science">{{cite journal |last1=Meise |first1=Kristine |last2=Garcia-Parra |first2=Carolina |title=Behavioural and environmental correlates of ''Philophthalmus zalophi'' infections and their impact on survival in juvenile Galapagos sea lions |journal=Marine Biology |date=October 2015 |volume=162 |issue=10 |pages=2107–2117 |doi=10.1007/s00227-015-2740-7|bibcode=2015MarBi.162.2107M |s2cid=83897007 }}</ref> The disease appears to be compounded by global warming, as the number of infectious stages of different parasites species has a strong correlation with temperature change. The Galapagos Islands go through seasonal changes in [[sea surface temperature]]s, which consist of high temperatures from the beginning of January through the month of May and lower temperatures throughout the rest of the year. Parasites surfaced in large numbers when the sea temperature was at its highest. Furthermore, data published in 2015 was collected by capturing sea lions in order to measure and determine their growth rates. Their growth rates were noted along with the sightings of parasites which were found under the eyelid. The results were that sea lions are affected by the parasites from the early ages of 3 weeks old up until the age of 4 to 8 months.<ref name="Web of Science" /> 

The parasites found in the eye fluke did serious damage to the eye. From the data collected, 21 of the 91 survived; with a total of 70 deaths in just a span of two years.<ref name="Web of Science" /> The parasites are attacking the pups at such young ages and causing the pups to not reach the age of reproduction. The death rates of the pups is surpassing the fertility rate by far. Since most pups are unable to reach the age of reproduction, the population is not growing fast enough to keep the species out of endangerment. Other parasites, like ''[[Anisakis]]'' and [[heartworm]], can also infect sea lions.

Australian sea lions (''Neophoca cinerea'') are also being affected by more frequent parasitic infections.<ref name="ScienceDirect">{{cite journal |last1=Higgins |first1=Damien |last2=Marcus |first2=Alan |last3=Gray |first3=Rachael |title=Health assessment of free-ranging endangered Australian sea lion (''Neophoca cinerea'') pups: Effect of haematophagous parasites on haematological parameters |journal=Comparative Biochemistry and Physiology |date=2015 |volume=184 |pages=132–143 |doi=10.1016/j.cbpa.2015.02.017 |pmid=25724096 }}</ref> The same method was used for the sea pups as on the Galapagos Islands, but in addition, the researchers in Australia took blood samples. The pups in Australia were being affected by hookworms, but they were also coming out in large numbers with warmer temperatures.<ref name="ScienceDirect"/> New Zealand sea lion pups (''Phocarctos hookeri'') were also affected in really early ages by hookworms (Uncinaria). The difference is that in New Zealand researchers took the necessary steps and began treatment.<ref name="EffectsOfHookworms">{{cite journal |last1=Chilvers |first1=B. L. |last2=Duignan |first2=P. J. |last3=Robertson |first3=B. C. |last4=Castinel |first4=A. |last5=Wilkinson |first5=I. S. |title=Effects of hookworms (''Uncinaria'' sp.) on the early growth and survival of New Zealand sea lion (''Phocarctos hookeri'') pups |journal=Polar Biology |date=February 2009 |volume=32 |issue=2 |pages=295–302 |doi=10.1007/s00300-008-0559-0 |bibcode=2009PoBio..32..295C |s2cid=10260797 }}</ref> The treatment seemed to be effective on the pups who have taken it. They found no traces of this infection afterwards. However, the percentage of pups who do have it is still relatively high at about 75%.<ref name="EffectsOfHookworms" /> Those pups who were treated had much better growth rates than those who did not. Overall parasites and hookworms are killing off enough pups to place them in endangerment. Parasites affect sea pups in various areas of the world. Reproductive success reduces immensely, survival methods, changes in health and growth have also been affected.

Similarly, climate change has resulted in increased toxic algae blooms in the oceans. These toxins are ingested by sardines and other fish which are then eaten by the sea lions, causing neurological damage and diseases such as epilepsy.<ref>{{Cite news|last=Richtel|first=Matt|date=2020-10-08|title=Brain Surgery for a 'Sweet Boy': Saving Cronutt the Sea Lion|language=en-US|work=The New York Times|url=https://www.nytimes.com/2020/10/08/science/sea-lion-epilepsy-surgery-cronutt.html|access-date=2020-10-13|issn=0362-4331|archive-date=13 October 2020|archive-url=https://web.archive.org/web/20201013144514/https://www.nytimes.com/2020/10/08/science/sea-lion-epilepsy-surgery-cronutt.html|url-status=live}}</ref>