Habitat Modelling on the Potential Impacts of Shipping Noise on Fin Whales (Balaenoptera physalus) in Offshore Irish Waters off the Porcupine Ridge

Little is known about the ecological importance of fin whales found year-round in southwestern offshore Irish waters. Understanding their ecology is important to reduce potential harm through any spatio-temporal overlap with commercial shipping and fishing activities. This study explored the potential environmental drivers and impacts of low-frequency shipping noise on fin whale calling at Porcupine Ridge using the presence/absence of call detections as a proxy for observed changes due to possible masking. Acoustic call data was collected at a low sampling rate (2 ksps) from the end of March 2016 to June 2016 (97 days) using a bottom-moored autonomous acoustic recorder with an omni-directional hydrophone. The high zero-inflated and binary nature of the data was addressed using generalised linear models. The results of our habitat modelling predicted call detections to increase significantly during night-time (p ≤ 0.01) with sea surface height and chlorophyll-a concentration (p ≤ 0.01), implying higher prey availability may occur on Porcupine Ridge. It also indicated a significant decrease in call detections with increasing shipping noise (p ≤ 0.01). Unfortunately, the model had a type II error. To provide robust results, a longer study not limited by data on the prey, and oceanographic drivers including spatial and temporal parameters is required. This study provides the foundations on which further ecological data could be added to establish management and mitigation measures to minimize the effects of shipping noise on fin whales.

A forgotten rodent from the Garden of Eden: what really happened to the long-tailed nesokia rat in the Mesopotamian marshes?

The greater part of expected mammalian extinctions will be of smaller-bodied mammals, including rats which are more generally known only as pests and carriers of pathogens. We address the long-tailed nesokia rat, which is among the least studied Palaearctic mammals. The species is known from merely five specimens, collected between March 1974 and January 1977 within a radius of 30 km around Qurna inside the seasonally flooded Mesopotamian marshes in southern Iraq. In the 1990s, this extensive aquatic habitat has been deliberately reduced to <15% of its original area and the IUCN expressed fear that such a disaster “almost certainly” caused the extinction of the long-tailed nesokia. Although the interventions after 2003 reversed the shrinking trend and marshes started to expand, the continuous presence of the long-tailed nesokia could not be unambiguously confirmed. We provide meagre evidence suggesting that the rat might be still present in the marshes. Next, our habitat modelling shows that the area of the long-tailed nesokia might be more extensive than expected with a highly suitable habitat covering 15,650 km2 of Mesopotamian marshland in Iraq (between Basra and Salah Ad Din provinces) and the Hawizeh Marshes in the adjacent Iranian Khuzestan.