Robinson Stacie, Falinski Kim, Johnson Devin, VanWormer Elizabeth, Shapiro Karen, Amlin Angela, Barbieri Michelle
NOAA, Hawaiian Monk Seal Research Program, Honolulu, USA.
UH, Water Resources Research Center, Honolulu, USA.
Ecohealth. 2024 Dec;21(2-4):141-154. doi: 10.1007/s10393-024-01678-7. Epub 2024 Jun 8.
Toxoplasmosis is a disease of primary concern for Hawaiian monk seals (Neomonachus schauinslandi), due to its apparently acute lethality and especially heavy impacts on breeding female seals. The disease-causing parasite, Toxoplasma gondii, depends on cats to complete its life cycle; thus, in order to understand how this pathogen infects marine mammals, it is essential to understand aspects of the terrestrial ecosystem and land-to-sea transport. In this study, we constructed a three-tiered model to assess risk of Hawaiian monk seal exposure to T. gondii oocysts: (1) oocyst contamination as a function of cat population characteristics; (2) land-to-sea transport of oocysts as a function of island hydrology, and (3) seal exposure as a function of habitat and space use. We were able to generate risk maps highlighting watersheds contributing the most to oocyst contamination of Hawaiian monk seal habitat. Further, the model showed that free-roaming cats most associated with humans (pets or strays often supplementally fed by people) were able to achieve high densities leading to high levels of oocyst contamination and elevated risk of T. gondii exposure.
弓形虫病是夏威夷僧海豹（Neomonachus schauinslandi）主要关注的一种疾病，因为它具有明显的急性致死性，尤其对繁殖期的雌性海豹影响巨大。致病寄生虫刚地弓形虫依赖猫来完成其生命周期；因此，为了了解这种病原体如何感染海洋哺乳动物，了解陆地生态系统以及陆地到海洋的传播情况至关重要。在本研究中，我们构建了一个三层模型来评估夏威夷僧海豹接触刚地弓形虫卵囊的风险：（1）作为猫种群特征函数的卵囊污染；（2）作为岛屿水文函数的卵囊陆地到海洋的传播，以及（3）作为栖息地和空间利用函数的海豹接触。我们能够生成风险地图，突出对夏威夷僧海豹栖息地卵囊污染贡献最大的流域。此外，该模型表明，与人类关联最大的自由放养猫（通常由人们额外喂食的宠物或流浪猫）能够达到高密度，导致高水平的卵囊污染和刚地弓形虫接触风险升高。
