AZFP論文：不列顛哥倫比亞省沿海三個地點磷蝦類晝夜垂直遷移季節性的地理差異
Abstract：
Diel vertical migration (DVM) is a behaviour observed across zooplankton taxa in marine and limnetic systems worldwide. DVM influences biogeochemical cycling and carbon drawdown in oceanic systems and alters prey availability for zooplanktivorous species. DVM has been well studied among zooplankton, and many exogenous and endogenous triggers as well as adaptive significances have been hypothesized. However, second-order variability in DVM timing, the deviation of DVM times to respective dawn and dusk times throughout the year, is a less-studied phenomenon that can help identify the factors influencing migration timing as well as demonstrate the changes of DVM behaviours within and across systems. Here, we quantified seasonal trends in second-order variability of DVM timing of euphausiids at Brooks Peninsula, Clayoquot Canyon, and Saanich Inlet near Vancouver Island, British Columbia, Canada, over multiple years using upward-facing moored echosounders. We used generalized additive mixed models to characterize this seasonality. DVM timing relative to civil twilight times showed strong seasonality at all locations, with euphausiids remaining near the surface longer than expected in spring and summer, and shorter than expected in winter. Euphausiids spent less time near the surface at Brooks Peninsula and Clayoquot Canyon than at Saanich Inlet throughout the year. Increased primary productivity in Saanich Inlet, which reduced light penetration and hid euphausiids from visual predators, likely drove this difference. Our findings confirm that proper understanding of DVM behaviours must account for seasonal variability due to context-specific oceanographic and ecological parameters. This is particularly pertinent when attempting to model the biogeochemical or predator–prey interactions influenced by DVM behaviours.
摘要：
晝夜垂直遷移（DVM）是在全球海洋和湖泊系統中的浮游動物分類群中觀察到的一種行為。DVM影響海洋系統中的生物地球化學循環和碳減少，改變了浮游動物物種的獵物可用性。DVM在浮游動物中得到了很好的研究，并提出了許多外源和內源性觸發因素以及適應性意義。然而，DVM時間的二階變異性，即DVM時間與全年黎明和黃昏時間的偏差，是一個研究較少的現象，可以幫助確定影響遷移時間的因素，并證明系統內和系統間DVM行為的變化。在這里，我們使用向上發射的系泊回聲探測儀，量化了多年來加拿大不列顛哥倫比亞省溫哥華島附近布魯克斯半島、克拉約科峽谷和薩尼奇灣幼發魚DVM時間二階變化的季節趨勢。我們使用廣義加性混合模型來表征這種季節性。與民用黃昏時間相比，DVM時間在所有地點都表現出強烈的季節性，幼發拉底獸在春季和夏季留在地表的時間比預期的長，在冬季比預期的短。全年，Euphausiids在布魯克斯半島和Clayoquot峽谷靠近地表的時間比在Saanich Inlet要短。Saanich Inlet初級生產力的提高，降低了光的穿透率，并使胡尾藻免受視覺捕食者的傷害，這可能是造成這種差異的原因。我們的研究結果證實，對DVM行為的正確理解必須考慮到由于特定環境的海洋和生態參數導致的季節性變化。當試圖模擬受DVM行為影響的生物地球化學或捕食者-獵物相互作用時，這一點尤其重要。
關鍵詞：主動聲學、生物海洋學、晝夜垂直遷徙、磷蝦、捕食者-獵物相互作用、時間序列、浮游動物。
