Skip to main content
U.S. flag

An official website of the United States government


Below is a list of available MMFS data releases.

Caligus Clemensi prevalence and counts on Clupea pallasii from Port Angeles Harbor, WA and from a controlled laboratory experiment conducted at USGS Marrowstone Marine Field Station, WA

We characterized a natural sea louse epizootic of Caligus clemensi and the effects of parasitism on Pacific herring Clupea pallasii in Port Angeles Harbor, WA, USA. Infestation prevalence on newly metamorphosed age0 Pacific herring reached 100% prevalence by mid-August. At this time, the mean louse intensity was 4.6 lice and a positive correlation occurred between louse intensity and Pacific herri

Infection prevalence and viral load in pacific herring exposed to erythrocytic necrosis virus (ENV) at 3 temperatures

Viral erythrocytic necrosis (VEN) is a disease of marine and anadromous fishes, which is poorly understood, largely because its causative iridovirus, erythrocytic necrosis virus (ENV), is intractable to cell culture. Natural VEN epizootics and observations studies in wild populations suggest that temperature may be an important disease cofactor. Here, a controlled laboratory exposure study provide

Entry and spread of specialist and generalist infectious hematopoietic necrosis virus (IHNV) genotypes in Chinook salmon, steelhead and sockeye salmon

Infectious hematopoietic necrosis virus (IHNV) represents one of the most critical challenges for salmonids in the Pacific Northwest. There are three genogroups of IHNV, designated U, M, and L; the U is further delineated into two subgroups, UC and UP, and the M is further delineated into four subgroups (MA – MD). The UP, UC and MD subgroups co-occur in the Columbia River Basin where the host spec

Histological and molecular testing of nuclear inclusion X in Pacific Razor clams from select locations in Washington, USA

Nuclear inclusion X (NIX), the etiological agent of bacterial gill disease in Pacific razor clams (Siliqua patula) was associated with host mortality events in coastal Washington, USA during the mid-1980s. Ongoing observations of truncated razor clam size distributions in Kalaloch Beach, Washington raised concerns that NIX continues to impact populations. We conducted a series of spatial and longi

DNA sequences from Ichthyophonid parasites

Data included are DNA sequences used to identify species boundaries among Ichthyophonus-like parasites. Sequences were generated for three gene regions from each parasite isolate. DNA sequences can be downloaded from GenBank ( as text or fasta files. Accession numbers for each sequence are included in the data table (.csv file). Data includes 87 sequences (99,383 tota

Survey of viral hemorrhagic septicemia virus in Pacific herring throughout the North Pacific Ocean

Throughout a 20-year biosurveillance period, viral hemorrhagic septicemia virus was isolated in low titers from only 6 / 7,355 opportunistically sampled adult Pacific herring, reflecting the typical endemic phase of the disease when the virus persists covertly. However, more focused surveillance efforts identified the presence of disease hot spots occurring among juvenile life history stages from

Laboratory challenge of Pacific herring Clupea pallasii to Vibrio anguillarum and V. ordallii

Controlled waterborne exposures of Pacific herring (Clupea pallasii) to Vibrio anguillarum and V. ordalii failed to result in overt signs of disease or mortality from vibriosis. Cumulative mortalities among Vibrio - exposed Pacific herring (3.3 - 5.0 percent) were similar to those of saline-exposed negative controls (10 percent) and significantly less (P less than 0.001) than those of Vibrio - exp