If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Planktonic invaders of the St. Lawrence estuarine transition zone: environmental factors controlling the distribution of zebra mussel veligers

$50.00 plus tax (Refund Policy)

Buy Article:

Abstract:

The St. Lawrence estuarine transition zone (ETZ) is a productive ecosystem supporting a larval fish nursery. Since 1994, Dreissena polymorpha veligers have become the dominant zooplankton (up to 260 individuals·L–1). The environmental factors controlling their distribution across the ETZ and their potential impact on the plankton were determined. Their horizontal distribution was limited by salinity, with maximum decreases in concentration at 2‰. A sharp decline in prey availability at >2‰ may be a secondary stressor for the veligers, in addition to the direct effects of salinity. Their vertical distribution was homogeneous throughout the water column, even in the presence of a pycnocline. Redundancy analysis showed that veliger concentrations were positively correlated with temperature and turbidity and negatively correlated with salinity and total phosphorus. Veligers were also positively correlated with chlorophyll a and picophytoplankton concentrations, suggesting little effect on their phytoplankton prey. Moreover, the veligers were positively correlated with the sestonic ratio of particulate to total phosphorus, indicating their positive association with good food quality. The veligers appear to have no severe negative impacts on the ETZ plankton community and are restricted to favourable conditions for their survival in the upstream, low salinity region of the ETZ.

La zone de transition estuarienne (ZTE) du fleuve Saint-Laurent est reconnue pour sa grande productivité, tel que démontré par son rôle de pouponnière de larves de poissons. Depuis 1994, les larves véligères de Dreissena polymorpha ont envahi le plancton de cette zone (jusqu'à 260 individus·L–1). Cette étude documente les facteurs environnementaux contrôlant leur distribution dans la ZTE et leurs impacts sur la communauté phytoplanctonique. Leur distribution horizontale était limitée par la salinité avec une diminution abrupte de leur abondance à 2 ‰. Un déclin simultané de la bio-disponibilité de leurs proies à >2 ‰ fut observé, impliquant que cette chute de bio-disponibilité pourrait constituer un stress additionnel à l'effet de la salinité. Leur distribution était homogène dans toute la colonne d'eau, même lors de la présence d'un gradient vertical de densité. Une analyse de redondance révèle que les véligères sont positivement corrélées à la température et à la turbidité, mais négativement corrélées à la salinité et au phosphore total. Les véligères sont positivement corrélées à leurs proies, i.e., à la biomasse de chlorophylle a et au picophytoplancton, impliquant qu'elles ne semblent pas avoir d'impacts sévères sur leurs proies phytoplanctoniques. Les véligères étaient positivement corrélées au seston de bonne qualité alimentaire et semblaient être associées aux conditions favorables pour leur croissance qui caractérisent les eaux de faibles salinités de la ZTE.

Document Type: Research Article

Publication date: October 1, 2003

More about this publication?
  • Published continuously since 1901 (under various titles), this monthly journal is the primary publishing vehicle for the multidisciplinary field of aquatic sciences. It publishes perspectives (syntheses, critiques, and re-evaluations), discussions (comments and replies), articles, and rapid communications, relating to current research on cells, organisms, populations, ecosystems, or processes that affect aquatic systems. The journal seeks to amplify, modify, question, or redirect accumulated knowledge in the field of fisheries and aquatic science. Occasional supplements are dedicated to single topics or to proceedings of international symposia.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more