American Society of Hirudotherapy

Aquatic invertebrate diversity in Apostle Islands and Isle Royale waters: comparison among habitats and sampling gears and to open Lake Superior

Research article published in Journal of Great Lakes research (2024)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportClinical TrialsTrebitz et al. · Journal of Great Lakes research, 2024

Abstract

Aquatic invertebrate composition in Great Lakes nearshore regions is known to differ from offshore, but studies representing the closest-to-land end of this gradient are primarily from estuaries and rivermouths having substantial watershed connectivity and anthropogenic influence. Here, we present data from aquatic invertebrate surveys conducted in two Lake Superior parks that are distanced from such watersheds and pressures, namely Apostle Islands National Lakeshore (APIS) and Isle Royale National Park (ISRO). Our intensive, multi-gear surveys from 99 APIS stations in 2017 and 165 ISRO stations in 2012 reveal a broad diversity of zooplankton and benthic/littoral macroinvertebrate taxa. Park samples yielded 29 zooplankton and >300 benthic/littoral taxa, with richness exceeding that of comparison nearshore datasets especially for aquatic insects, leeches, and mites. Station depth was a major factor structuring invertebrates, and benthic/littoral densities were highest and composition most diverse at shallow stations having aquatic vegetation. Species composition and taxa accumulation patterns differed considerably among sampling gears, highlighting the value of multi-gear surveys. Several park mollusk and insect species matched 'special concern' listings, and two non-native cladocerans were very abundant. These two surveys added 11 new species to the aquatic macroinvertebrates known from Lake Superior, highlighting the importance of these park in harboring biodiversity and the importance of individualized assessments of places not well represented in more routine lakewide biological monitoring. Our data are available as baselines for future biological surveys and trend assessments.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article

Summary

Peer-reviewed clinical and outcomes research relevant to medicinal leech therapy and its biology. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This multi-gear field survey of aquatic invertebrates in two Lake Superior parks documented broad biodiversity (29 zooplankton and over 300 benthic/littoral taxa), with richness exceeding comparison nearshore datasets especially for aquatic insects, leeches, and mites, and added 11 new macroinvertebrate species to those known from Lake Superior. Its relevance to hirudotherapy is ecological and foundational: it underscores leeches as a diverse component of freshwater fauna and the importance of habitat baselines, context that supports responsible sourcing and conservation awareness around the broader leech taxa from which the medicinal species derives. Caveat: this is a biodiversity/ecological survey, not a biomedical study; it does not examine Hirudo medicinalis, the leech secretome, or any therapeutic application, and has no direct bearing on clinical evidence.

Citation

Aquatic invertebrate diversity in Apostle Islands and Isle Royale waters: comparison among habitats and sampling gears and to open Lake Superior.

Trebitz et al. · Journal of Great Lakes research, 2024

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.