Determining the benefits and limitations of legacy ichthyoarchaeological collections: a Pacific Islands example

Legacy faunal collections remain an indispensable yet untested resource for Pacific Island ichthyoarchaeology. We analyse fish remains from nine late pre-contact (AD1400-1795) sites on leeward Moloka‘i, Hawaiian Islands, excavated in 1952, augmented by a controlled 1 m² excavation at one rock shelter (Mo1) in 2019 to evaluate benefits and limitations of legacy assemblages. Taxa were quantified by NISP and compared using diversity indices, chord distances, and correspondence analysis. Despite the 1952 recovery that favored larger elements, relationships between excavated volume, identified fish bone counts, and total fish bone weight indicate broadly consistent field protocols, permitting cautious between-site comparisons. Concentration values range from 3.7 to 191.3 g/m³, indicating marked variability in fishing intensity among sites. Reconstructed fish weights enabled us to infer size structure, fishing intensity and habitat exploitation. Comparison between 1952 and 2019 Mo1 site results reflected finer-mesh recovery of small-bodied reef taxa in the 2019 assemblage. Compositional analyses reveal unusually high representation of threadfin (moi, Polynemidae, Polydactylus sexfilis) across the region. Otoliths from 2019 include the first Pacific Islands archaeological record of silverside (‘iao, Atherinidae Atherinomorus insularum). We demonstrate that, when carefully contextualized and augmented by targeted, fine-screen additional excavation, legacy collections can inform on habitat use, capture strategies, fish size, fish population structure and seasonality.