The effectiveness of dedicated observers in reducing risks of marine mammal collisions with ferries: A test of the technique

Lessons From Placing an Observer on Commercial Cargo Ships Off the U.S. West Coast: Utility as an Observation Platform and Insight Into Ship Strike Vulnerability

“…This is consistent with findings in other areas regarding the value of dedicated marine mammal observers placed on board ferries and cruise ships (Gende et al, 2011;Harris et al, 2012;Williams et al, 2016). Weinrich et al (2010) demonstrated that observers aboard fast ferries detected whales faster and at larger distances than the crew. Commercial vessels bridge height above the sea surface, the wide field of view, all designed for safe operations and the ships stability, make an excellent marine mammal viewing platform.…”

“…Placing dedicated marine mammals observers on board vessels has been proposed as an effective method for getting sighting information and helping to avoid collisions with large whales (Weinrich, 2004;ACCOBAMS, 2005;David et al, 2005;Weinrich et al, 2010;Gende et al, 2011;Couvat and Gambaiani, 2013). We report on a pilot program putting an observer on ships transiting between U.S. West Coast ports to document sightings along these routes, help quantify the threat to whales from ships and also evaluate the feasibility of using these platforms as an expanded source of sighting reports which were all part of the recommendations of the JWG.…”

Factors affecting whale detection from large ships in Alaska with implications for whale avoidance

“…comm., 31 January 2011). An experiment comparing whale detections by dedicated observers to those by ship captains aboard fast ferries demonstrated that dedicated observers detected whales faster and at greater distances than the captain, who was often engaged in other activities (Weinrich et al 2010). We also note that while bridge personnel are not exposed to inclement weather and possible interference by cruise ship passengers like the observer, they are also not equipped with rangefinder binoculars and nor does their search image focus solely on whales.…”

A Bayesian approach for understanding the role of ship speed in whale–ship encounters

“…It is beyond the scope of our study to identify the mechanism underlying the speed-distance relationship, although we feel the results are not likely a function of ship avoidance behavior of the whales. Cruise ships in our study area have no designated marine mammal observer on the bridge, which can influence the probability of detecting whales (Weinrich et al 2010) needed prior to initiating avoidance measures. In addition, we regularly communicated with the ship captains/pilots and many have stated that when a whale is detected they generally retain course and speed, noting that the confined space within Glacier Bay hinders large course alterations.…”