<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The possibility of doing a back assessment of the ecological status of a lake based on archival bathymetric maps indicating areas overgrown with rushes and aquatic vegetation was verified. This assessment was assumed to be in accordance with that performed with the official Polish macrophyte-based method for lake assessment (Ecological State Macrophyte Index, ESMI). The study was conducted on Lake Dobrąg located in the Warmian-Masurian Voivodeship (surface area - 108 ha, maximum depth - 27.9 m, mean depth - 11.6 m). It included the hydroacoustic distribution of submerged macrophytes along 85 evenly distributed belt transects (perpendicularl to the shore line), creating a bathymetric chart and maps of vegetation occurrence and identifying areas occupied by hydrophytes (C<sub>max</sub>) and the maximum depth of lake colonization (Z). Analogous data were read from archival bathymetric chart dating from 1964-1968. The values obtained were compared with the means (and their confidence intervals) of 83 stratified lakes in Poland in different ecological status classes. Analysis of changes indicated that the ecological status of the lake had deteriorated. In the mid-1960s, the status of the lake was less than “very good” while the current status borders between “good” and “moderate.” The results indicate that the proposed method could be useful when attempting to assess changes in ecological status using archival bathymetric charts showing areas overgrown with vegetation and the distribution of it in lakes.</p></abstract>

The possibility of doing a back assessment of the ecological status of a lake based on archival bathymetric maps indicating areas overgrown with rushes and aquatic vegetation was verified. This assessment was assumed to be in accordance with that performed with the official Polish macrophyte-based method for lake assessment (Ecological State Macrophyte Index, ESMI). The study was conducted on Lake Dobrąg located in the Warmian-Masurian Voivodeship (surface area - 108 ha, maximum depth - 27.9 m, mean depth - 11.6 m). It included the hydroacoustic distribution of submerged macrophytes along 85 evenly distributed belt transects (perpendicularl to the shore line), creating a bathymetric chart and maps of vegetation occurrence and identifying areas occupied by hydrophytes (Cmax) and the maximum depth of lake colonization (Z). Analogous data were read from archival bathymetric chart dating from 1964-1968. The values obtained were compared with the means (and their confidence intervals) of 83 stratified lakes in Poland in different ecological status classes. Analysis of changes indicated that the ecological status of the lake had deteriorated. In the mid-1960s, the status of the lake was less than “very good” while the current status borders between “good” and “moderate.” The results indicate that the proposed method could be useful when attempting to assess changes in ecological status using archival bathymetric charts showing areas overgrown with vegetation and the distribution of it in lakes.

An attempt to assess the ecological status of a lake based on historical and current maps of submerged vegetation

Fisheries & Aquatic Life

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The possibility of doing a back assessment of the ecological status of a lake based on archival bathymetric maps indicating areas overgrown with rushes and...

An attempt to assess the ecological status of a lake based on historical and current maps of submerged vegetation

Published Online: May 13, 2017

Page range: 33 - 42

Received: Jan 31, 2017

Accepted: Mar 28, 2017

DOI: https://doi.org/10.1515/aopf-2017-0004

Keywords
hydroacoustics, aquatic vegetation, assessing ecological status

© Archives of Polish Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

An attempt to assess the ecological status of a lake based on historical and current maps of submerged vegetation

Published Online: May 13, 2017

Page range: 33 - 42

Received: Jan 31, 2017

Accepted: Mar 28, 2017

DOI: https://doi.org/10.1515/aopf-2017-0004

Keywordshydroacoustics, aquatic vegetation, assessing ecological status

© Archives of Polish Fisheries

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
hydroacoustics, aquatic vegetation, assessing ecological status