Vertical distribution of alewife in the Lake Ontario offshore: Implications for resource use

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F17%3A00480484" target="_blank" >RIV/60077344:_____/17:00480484 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1016/j.jglr.2017.07.007" target="_blank" >http://dx.doi.org/10.1016/j.jglr.2017.07.007</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jglr.2017.07.007" target="_blank" >10.1016/j.jglr.2017.07.007</a>

Result language

angličtina

Original language name

Vertical distribution of alewife in the Lake Ontario offshore: Implications for resource use

Original language description

Oligotrophication of Lake Ontario has led to increased water clarity and an increased proportion of zooplankton residing in the metalimnion during the day, which may affect the utilization of different depth regions for planktivorous fish. We investigated day and night distributions of fish using hydroacoustics and suspended vertical gillnets during the summer of 2013 when a deep chlorophyll layer (DCL) was established. We related fish distributions to concurrent measures of temperature and prey (zooplankton) density. Alewife dominated in vertical gill net catches, indicating that most acoustic targets were alewife. Alewife schooled during the day in the bottom of the mixed layer, and at dusk alewife schools broke up and fish moved towards the surface. We hypothesize this movement followed migrating zooplankton to allow feeding at night, alewife sampled from vertical gillnets fed on cyclopoid copepods and cladocerans, prey groups that migrate into the epilimnion at night. Some alewife remained at the bottom of the mixed layer at night and these fish ate deep-water calanoid copepods such as Limnocalanus. Vertical distributions were best predicted by temperature and the interaction between temperature and zooplankton density. We include uplooking acoustics data to complement our downlooking datasets, which provided evidence for potential bias in downlooking acoustic assessments of alewife due to high proportions of alewife found in the surface exclusion zone. Our approach combining several datasets provides a new perspective to understand summer diel distribution of alewife and the factors driving their distribution.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10617 - Marine biology, freshwater biology, limnology

Project

<a href="/en/project/LD15021" target="_blank" >LD15021: Why are you there? Fish distribution and activity in large standing waters.</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Great Lakes Research

ISSN

0380-1330

e-ISSN

—

Volume of the periodical

43

Issue of the periodical within the volume

5

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

823-837

UT code for WoS article

000411533900006

EID of the result in the Scopus database

2-s2.0-85027156718