The whales stay in the lagoons for two to three months, from January to the middle of March, which allows the calves to build up a thick layer of blubber to sustain them on the northward journey and to keep them warm in the colder waters of the Arctic.
Laguunidesse jäävad hallvaalad kaheks - kolmeks kuuks jaanuarist märtsi keskpaigani, nii et noored vaalad saavad koguda põhja poole rännuks rasvavaru, mis neile Põhja - Jäämere külmades vetes sooja annab.