Dan E. Kelley

Provides tools for simulating the biophysical effects of vessel-strikes on whales. The aim is to support the evaluation of marine policies limiting ship speeds through regions in which whales reside. This is important because ship strikes are a major source of lethality for several whale species, including the critically endangered North Atlantic right whale. In this analysis, whales are modelled with a four-layer system comprising skin, blubber, sub-layer (muscle or organ) and bone. Reasonable values for the material properties of these layers, along with other factors such as whale surface area and mass, are provided for a variety of whale species. Similarly, key values are provided for several ship types. The collision is modelled according to Newtonian dynamics, with stresses and strains within the whale layers being simulated over time. The simulation results are analyzed in the context of whale-strike data, to develop a Lethality Index for the whale in the modelled collision. For the underlying science, see Kelley and other "Assessing the Lethality of Ship Strikes on Whales Using Simple Biophysical Models." (2021) . For more on the R code, see Kelley "'whalestrike': An R package for simulating ship strikes on whales" (2024) .

An R package named argoFloats has been developed to facilitate identifying, downloading, caching, and analyzing oceanographic data collected by Argo profiling floats. The analysis phase benefits from close connections between argoFloats and the oce package, which is likely to be familiar to those who already use R for the analysis of oceanographic data of other kinds. This paper outlines how to use argoFloats to accomplish some everyday tasks that are particular to Argo data, ranging from downloading data and finding subsets to handling quality control and producing a variety of diagnostic plots. The benefits of the R environment are sketched in the examples, and also in some notes on the future of the argoFloats package.

Studies of ship strikes on whales often focus on large vessels (>20 m), with attention to their speeds and the resulting risk of lethality. Smaller coastal vessels also co‐occur with whales, resulting in collisions that merit study. To cast light on injuries caused by vessels of all sizes, we used knowledge of right whale anatomy and Newtonian mechanics to construct simple models that predict the mechanical stresses experienced by whales during collisions. By comparing our predictions with published models and with data from ship strikes on various whale species, we developed a model for lethal injury as a function of several vessel and whale properties, finding that collisions that create stresses in excess of 0.241 MPa were likely to cause lethal injuries to large whales. Furthermore, this model has revealed that (1) vessels of all sizes can yield stresses higher than this critical level, and (2) large vessels produce stresses much larger than this even when travelling at reduced speeds (i.e., 10 knots). The model is fast enough to power an interactive GUI‐based tool (in R) and flexible enough to simulate strikes by vessels of different masses and speeds upon whales of different species, sizes, and physical conditions.

To address a need for science‐based advice on issues of resource exploration, two oceanographic moorings were placed on the abyssal slope of northwest Flemish Cap from July 2013 to July 2014. These yielded some of the first long‐term moored measurements of velocity, temperature, and salinity in the region. Hydrographic and lowered‐ADCP measurements made during mooring deployment and recovery reveal that the deep Labrador Current flows approximately along isobaths between water depths of 1,200 and 2,200 m. However, these snapshots differ significantly, with stronger currents observed during the deployment survey. The mooring data, obtained near the 1,500 m isobath, reveal a complex temporal variation of the current. The velocity spectrum is dominated by a peak at a period of approximately 21 days, with power increasing with depth in the water column and varying through the year. In other boundary‐current studies, variations in the several‐week band have been attributed to baroclinic topographic Rossby waves, but with just two widely spaced moorings, we cannot infer the wave number and test for such waves using the dispersion relationship. However, an indirect estimate of wave number can be made by examining the variation of spectral power with depth, and doing this yields results that are reasonably consistent with a linear theory of baroclinic topographic Rossby waves for water of constant stratification over a planar slope. This agreement is somewhat surprising, given the simplicity of the theory and the complexity of the domain, but it appears to offer a clear indication of the importance of baroclinic vorticity dynamics in this region.