Fish Fossils

Nearly all coastal shelters contain fish bones from the scat of river otters. It is not uncommon to find these fish bones over a km from the coast and over 200 meters above sea level in caves that make good carnivore dens. In some cases they occur in thick beds from long-term occupation. Recent deposits can be seen in feces and in localized piles near otter nests in some cases. These deposits, though dominated by fish remains, frequently contain fragments of juvenile otters, birds, and various invertebrates. Small numbers of fish bones are present throughout much of the older sediment from On Your Knees Cave, so the fish record extends back beyond the Last Glacial Maximum.

The photos above are of fish bones from El Capitan Cave. The left photo is of washed sediment composed almost entirely of fish bones from otter scat. The right photo illustrates examples of fish otoliths, vertebrae, spines, and jaws.

 

Becky Wingen (left) and Susan Crockford (right) in their bone collection at the University of Victoria Department of Archaeology.
Unlike the mammal and bird remains, the fish were not identified by the paleontologists of the project (Tim Heaton and Fred Grady). In fact, it took us several years after the excavation of El Capitan Cave to find someone competent and willing to work on them. Luckily we found two ladies who are experts at identifying fragmentary fish remains from marine mammal scats in the Pacific Northwest: Susan Crockford and Becky Wingen of Pacific Identifications, Inc., in Victoria, British Columbia (see photo at right). Thanks to their work, over 50 species of fish have been identified so far from caves of Prince of Wales Island (see table below). This far outnumbers the species of mammals or birds that have been recovered.

 

Fish Taxa Recovered from Caves
of Prince of Wales Island

Class Osteichthyes                         Fish common names

Order Clupeiformes
  Family Clupeidae
    Clupea pallasi                         Pacific Herring

Order Salmoniformes
  Family Osmeridae
    Mallotus villosus                      Capelin
    Thaleichthys cf. pacificus             Eulachon

  Family Salmonidae
   Oncorhynchus sp.                        Salmon

Order Gadiformes
  Family Gadidae
    Gadus macrocephalus                    Pacific Cod
    Microgadus cf. proximus                Pacific Tomcod
    Theragra chalcogramma                  Walleye Pollack

Order Gasterosteiformes
  Family Gasterosteidae
    Gasterosteus aculeatus                 Threespine Stickleback

Order Scorpaeniformes
  Family Scorpaenidae
    Sebastes sp.                           Rockfish

  Family Anoplopomatidae
    Anoplopoma fimbria                     Sablefish

  Family Hexagrammidae
    Hexagrammos cf. decagrammus            Kelp Greenling
    Hexagrammos cf. lagocephalus           Rock Greenling
    Hexagrammos cf. stelleri               Whitespotted Greenling
    cf. Ophiodon elongatus                 Lingcod

  Family Cottidae
    cf. Artedius fenestralis               Padded Sculpin
    Cottus aleuticus                       Coastrange Sculpin
    Cottus cf. asper                       Prickly Sculpin
    Enophrys bison                         Buffalo Sculpin
    Enophrys cf. lucasi                    Leister Sculpin
    Enophrys sp. (additional)              Sculpin
    Hemilepidotus sp.                      Irish Lord
    Hemitripterus cf. bolini               Bigmouth Sculpin
    Leptocottus cf. armatus                Pacific Staghorn Sculpin
    Malacocottus sp.                       Sculpin
    Myoxocephalus cf. jaok                 Plain Sculpin
    Myoxocephalus cf. polyacanthocephalus  Great Sculpin
    Myoxocephalus cf. rucosus              Warty Sculpin
    Oligocottus cf. maculosus              Tidepool Sculpin
    cf. Scorpaenichthys marmoratus         Cabezon

  Family Agonidae
    Podothecus cf. acipenserinus           Sturgeon Poacher

  Family Cyclopteridae
    Aptocyclus cf. ventricosus             Smooth Lumpsucker

Order Perciformes
  Family Bathymasteridae
    cf. Ronquilus jordani                  Northern Ronquil

  Family Stichaeidae
    Anoplarchus cf. purpurescens           High Cockscomb
    Chirolophis sp.                        Warbonnet
    Lumpenus cf. maculatus                 Daubed Shanny
    Lumpenus cf. sagitta                   Snake Prickleback
    Xiphister cf. atropurpureus            Black Prickleback
    Xiphister cf. mucosus                  Rock Prickleback

  Family Pholidae                          Gunnels
    Apodichthys cf. flavidus               Penpoint Gunnel
    Pholis cf. laeta                       Crescent Gunnel

  Family Anarhichadidae
    Anarrhichthys ocellatus                Wolf-eel

  Family Trichodontidae
    Trichodon trichodon                    Pacific Sandfish

  Family Ammodytidae
    Ammodytes hexapterus                   Pacific Sand Lance

Order Pleuronectiformes
  Family Pleuronectidae
    Atheresthes cf. stomias                Arrowtooth Flounder
    cf. Hippoglossus stenolepis            Pacific Halibut
    Microstomus cf. pacificus              Dover Sole
    Platichthys stellatus                  Starry Flounder
    Pleuronectes asper                     Yellowfin Sole
    Pleuronectes cf. biliniata             Rock Sole
    Pleuronectes cf. vetulus               English Sole

Different fish assemblages have been found at different sites. The coast near On Your Knees Cave is steep and rocky and receives strong waves from Sumner Strait. The fish fauna from that cave is dominated by Irish lords, rockfishes, greenlings, pricklebacks, and other species that prefer high energy coasts. The fish fauna from El Capitan Cave is dominated by flatfishes and sculpins such as Myoxocephalus spp., Cottus asper, and C. aleuticus which prefer brackish water and shallow muddy bottoms. These conditions are present in the El Capitan Passage near El Capitan Cave (in the narrow, shallow channel between Prince of Wales and Kosciusko Islands). So the differences reflect local coastal conditions around each cave.

Only three fish samples have been radiocarbon dated thus far. All are from El Capitan Cave, and all date to the early Holocene. Results from additional caves will be presented in the future. Another upcoming project is to use fish otoliths (ear stones, see photo above) from the caves to determine past ocean temperatures and fish growth rates.

   
© 2002 by Timothy H. Heaton