Dr. Susan Crockford notes:
Walrus researchers from the US Geological Survey have a new report on the history of walrus haulouts in the Chukchi and Bering Seas – yet their media efforts (via press release and interviews) fail to mention the relationship between fluctuating size of walrus haulouts and fluctuating walrus population size that is evident in that history. In fact, overall population size is not mentioned at all.
Two articles came out over the weekend that announced the results of this new joint US-Russian initiative [PBS, Walrus beaching in Alaska might not be as harmful as it looks. Here’s why – 31 July 2016 and ADN, Alaska and Russia join forces to create 160-year database of walrus haulouts – 31 July 2016]
But neither articles nor the new USGS paper they are touting (Fischback et al. 2016) mention the huge summer/fall haulouts of females, calves, and juveniles that were documented in the 1970s that coincided with the huge population size at that time, which crashed in the 1980s.
Only now has the population grown (to at least 200,000) to the point that huge haulouts are again being reported – conservation has done it’s job. But when walrus numbers get too high the animals out-strip their food source and numbers plummet, as they did in the 1980s (Fay et al. 1989; Garlich-Miller et al. 2011). See my fully referenced summary paper, Crockford 2014 (On The Beach: Walrus Haulouts are Nothing New).
Full post with more details here: https://polarbearscience.com/2016/08/02/usgs-report-on-history-of-walrus-haulouts-leaves-out-correlation-with-population-size/