Lauria Valentina, Power Anne Marie, Lordan Colm, Weetman Adrian, Johnson Mark P
Ryan Institute, School of Natural Sciences, National University of Ireland, Galway, University Road, Galway, Ireland.
Department of Zoology, School of Natural Sciences, Ryan Institute, National University of Ireland, Galway, University Road, Galway, Ireland.
PLoS One. 2015 Feb 13;10(2):e0117006. doi: 10.1371/journal.pone.0117006. eCollection 2015.
Knowledge of the spatial distribution and habitat associations of species in relation to the environment is essential for their management and conservation. Habitat suitability models are useful in quantifying species-environment relationships and predicting species distribution patterns. Little is known, however, about the stability and performance of habitat suitability models when projected into new areas (spatial transferability) and how this can inform resource management. The aims of this study were to model habitat suitability of Norway lobster (Nephrops norvegicus) in five fished areas of the Northeast Atlantic (Aran ground, Irish Sea, Celtic Sea, Scotland Inshore and Fladen ground), and to test for spatial transferability of habitat models among multiple regions. Nephrops burrow density was modelled using generalised additive models (GAMs) with predictors selected from four environmental variables (depth, slope, sediment and rugosity). Models were evaluated and tested for spatial transferability among areas. The optimum models (lowest AICc) for different areas always included depth and sediment as predictors. Burrow densities were generally greater at depth and in finer sediments, but relationships for individual areas were sometimes more complex. Aside from an inclusion of depth and sediment, the optimum models differed between fished areas. When it came to tests of spatial transferability, however, most of the models were able to predict Nephrops density in other areas. Furthermore, transferability was not dependent on use of the optimum models since competing models were also able to achieve a similar level of transferability to new areas. A degree of decoupling between model 'fitting' performance and spatial transferability supports the use of simpler models when extrapolating habitat suitability maps to different areas. Differences in the form and performance of models from different areas may supply further information on the processes shaping species' distributions. Spatial transferability of habitat models can be used to support fishery management when the information is scarce but caution needs to be applied when making inference and a multi-area transferability analysis is preferable to bilateral comparisons between areas.
了解物种的空间分布及其与环境的栖息地关联对于它们的管理和保护至关重要。栖息地适宜性模型有助于量化物种与环境的关系，并预测物种分布模式。然而，对于栖息地适宜性模型在新区域的稳定性和性能（空间可转移性）以及这如何为资源管理提供信息，我们知之甚少。本研究的目的是模拟东北大西洋五个捕捞区域（阿兰海床、爱尔兰海、凯尔特海、苏格兰近岸和弗拉登海床）中挪威龙虾（Nephrops norvegicus）的栖息地适宜性，并测试栖息地模型在多个区域之间的空间可转移性。使用广义相加模型（GAM）对挪威龙虾洞穴密度进行建模，预测变量从四个环境变量（深度、坡度、沉积物和粗糙度）中选取。对模型进行评估并测试其在各区域之间的空间可转移性。不同区域的最优模型（最低AICc）总是包含深度和沉积物作为预测变量。洞穴密度通常在较深和较细的沉积物中更大，但个别区域的关系有时更为复杂。除了包含深度和沉积物外，不同捕捞区域的最优模型也有所不同。然而，在空间可转移性测试中，大多数模型能够预测其他区域的挪威龙虾密度。此外，可转移性并不依赖于使用最优模型，因为竞争模型也能够在新区域实现类似水平的可转移性。模型“拟合”性能与空间可转移性之间的一定程度的解耦支持在将栖息地适宜性地图外推到不同区域时使用更简单的模型。不同区域模型的形式和性能差异可能提供有关塑造物种分布过程的更多信息。当信息稀缺时，栖息地模型的空间可转移性可用于支持渔业管理，但在进行推断时需要谨慎，多区域可转移性分析优于区域间的双边比较。
