California Sea Lion Stranding Records from Quantifying the linkages between California sea lion (Zalophus californianus) strandings and particulate domoic acid concentrations at piers across Southern California

Pacific Marine Mammal Center (PMMC) is a member of the West Coast Marine Mammal Stranding Network, which was established under the United States Marine Mammal Protection Act by the National Oceanic and Atmospheric Administration (NOAA) to respond to stranded marine mammals. PMMC rescues, rehabilitates, and releases sick and injured marine mammals along the Orange County coastline, which is approximately 68 km of the Southern California coastline (Figure 1). All marine mammal rescue and rehabilitation activities are conducted by PMMC under a Stranding Agreement with National Marine Fisheries Service/NOAA. Patient case records from 2015-2019 for California sea lions (hereafter, sea lions) were reviewed and collated for each animal’s case presentation including sex, age class, seizure activity, postictal signs, comatose, abortion, and whether the sea lion was diagnosed by the attending veterinarian with domoic acid intoxication following the behavioral diagnostic criteria outlined by Gulland et al., (2002). Multiple veterinarians made diagnoses during the time series based on these criteria which may have introduced some variation in the diagnosis of domoic acid intoxication during the study period. Age classes were defined following Greig et al. (2005) using dentition, straight length, pregnancy status, and sexual dimorphism to classify a sea lion’s age class. The following demographic categories are included in this study: juvenile/subadult male, subadult female, adult male, and adult female. Younger sea lions in the pup and yearling age classes were excluded as sea lions within these age classes are generally the most common patients at the center and often strand due to malnutrition (Bejarano et al., 2008a), and rarely present with acute or chronic domoic acid intoxication during blooms. Adult and subadult age classes are the most commonly affected by domoic acid intoxication (Bejarano et al., 2008a). Only live sea lions that were rescued on the Orange County coastline, brought to PMMC's facility, and assessed by the attending veterinarian were included. Adult and subadult sea lions that died on the beach were excluded from the study cohort because an attending veterinarian could not assess clinical signs to diagnosis domoic acid intoxication prior to death.太平洋海洋哺乳动物中心（Pacific Marine Mammal Center, PMMC）是西海岸海洋哺乳动物搁浅网络（West Coast Marine Mammal Stranding Network）的成员单位。该网络由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）依据《美国海洋哺乳动物保护法》（United States Marine Mammal Protection Act）设立，旨在对搁浅海洋哺乳动物开展应急响应。PMMC负责在奥兰治县海岸线——即南加州约68公里长的海岸带（图1）——对患病、受伤的海洋哺乳动物实施救助、康复与放归工作。所有海洋哺乳动物救助及康复活动均由PMMC依据与国家海洋渔业局/NOAA签订的《搁浅救助协议》（Stranding Agreement）开展。 本研究回顾整理了2015至2019年间的加州海狮（下文简称海狮）病例档案，涵盖每只受试动物的病例表现，包括性别、年龄组、癫痫发作症状、发作后体征、昏迷状态、流产情况，以及执业兽医是否依据Gulland等人（2002）提出的行为学诊断标准确诊其罹患软骨藻酸中毒（domoic acid intoxication）。研究期间，多名兽医基于上述标准进行诊断，这可能在研究周期内为软骨藻酸中毒的诊断引入一定偏差。年龄组划分参照Greig等人（2005）的方法，通过牙齿磨损情况、体长、妊娠状态及性别二态性对海狮的年龄组进行分类。本研究纳入以下种群分类：幼年/亚成年雄性、亚成年雌性、成年雄性及成年雌性。幼崽及一岁龄年龄组的幼年海狮被排除出研究队列：此类海狮通常是中心最常见的收治病例，常因营养不良搁浅（Bejarano et al., 2008a），且在藻华爆发期间极少表现出急性或慢性软骨藻酸中毒症状。成年及亚成年年龄组是最易受软骨藻酸中毒影响的群体（Bejarano et al., 2008a）。本研究仅纳入在奥兰治县海岸线获救、送至PMMC中心并经执业兽医评估的活海狮。在海滩上死亡的成年及亚成年海狮被排除出研究队列，原因是兽医无法在其死亡前评估临床体征以确诊软骨藻酸中毒。