Hoover-Miller A, Dunn J L, Field C L, Blundell G, Atkinson S
Alaska SeaLife Center, 301 Railway Ave, PO Box 1329, Seward, AK 99664, USA.
Dis Aquat Organ. 2017 Sep 20;126(1):1-12. doi: 10.3354/dao03153.
Populations of harbor seal Phoca vitulina in the Gulf of Alaska have dramatically declined during the past 4 decades. Numbers of seals in Glacier Bay, in southeast Alaska, USA, have also declined despite extensive protection. Causes of the declines and slow recovery are poorly understood. Brucellosis is a zoonotic disease that adversely affects reproduction in many domestic species. We measured the seroprevalence of Brucella antibodies in 554 harbor seals in 3 Alaska locations: Prince William Sound (PWS), Glacier Bay (GB), and Tracy Arm Fords Terror (TAFT) Wilderness Area. Objectives included testing for regional, sex, age, and female reproductive state differences in Brucella antibody seroprevalence, persistence in titers in recaptured seals, and differences in titers between mother seals and their pups. Overall, 52% of adults (AD), 53% of subadults (SA), 77% of yearlings (YRL), and 26% of <5 mo old pups were seropositive. Matched mother-pup samples were consistent with dependent pups acquiring maternal passive immunity to Brucella. Results show higher seroprevalence (64%) for AD and SA seals in the depressed and declining populations in PWS and GB than in TAFT (29%). Lactating females were less likely to be seropositive than other AD females, including pregnant females. Further research is needed to seek evidence of Brucella infection in Alaskan harbor seals, identify effects on neonatal viability, and assess zoonotic implications for Alaska Natives who rely on harbor seals for food.
在过去40年里，阿拉斯加湾的港海豹（Phoca vitulina）种群数量急剧下降。尽管受到广泛保护，但美国阿拉斯加东南部冰川湾的海豹数量仍在减少。种群数量下降及恢复缓慢的原因尚不清楚。布鲁氏菌病是一种人畜共患病，会对许多家养物种的繁殖产生不利影响。我们测量了阿拉斯加3个地点的554只港海豹体内布鲁氏菌抗体的血清阳性率，这3个地点分别是威廉王子湾（PWS）、冰川湾（GB）和特雷西峡湾-福特斯恐怖湾（TAFT）荒野地区。目标包括检测布鲁氏菌抗体血清阳性率在区域、性别、年龄和雌性繁殖状态方面的差异，重新捕获海豹时抗体滴度的持续性，以及母海豹与其幼崽之间抗体滴度的差异。总体而言，52%的成年海豹（AD）、53%的亚成年海豹（SA）、77%的一岁龄海豹（YRL）和26%的5月龄以下幼崽血清呈阳性。配对的母幼样本表明，幼崽获得了对布鲁氏菌的母源被动免疫。结果显示，在威廉王子湾和冰川湾数量减少和下降的种群中，成年和亚成年海豹的血清阳性率（64%）高于特雷西峡湾-福特斯恐怖湾（29%）。与其他成年雌性海豹（包括怀孕雌性）相比，哺乳期雌性海豹血清呈阳性的可能性较小。需要进一步研究以寻找阿拉斯加港海豹感染布鲁氏菌的证据，确定其对新生儿生存能力的影响，并评估对依赖港海豹作为食物的阿拉斯加原住民的人畜共患病影响。
