Some of these are quite inexpensive. Others are more costly, such as the $15,000 miniature electronic apparatus, with camcorder, that is used to study the diving habits of seals.
Mõned neist meetoditest on üsna odavad, teised aga üpris kallid, nagu 15 000 dollarit maksev videokaameraga varustatud miniatuurne elektrooniline aparaat, mida kasutatakse hüljeste sukeldumise uurimiseks.