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Coding early naturalists' accounts into long-term fish community changes in the Adriatic Sea (1800-2000).

Fortibuoni T, Libralato S, Raicevich S, Giovanardi O, Solidoro C - PLoS ONE (2010)

Bottom Line: Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species.This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources.To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Oceanography, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Sgonico, Italy. tfortibuoni@ogs.trieste.it

ABSTRACT
The understanding of fish communities' changes over the past centuries has important implications for conservation policy and marine resource management. However, reconstructing these changes is difficult because information on marine communities before the second half of the 20(th) century is, in most cases, anecdotal and merely qualitative. Therefore, historical qualitative records and modern quantitative data are not directly comparable, and their integration for long-term analyses is not straightforward. We developed a methodology that allows the coding of qualitative information provided by early naturalists into semi-quantitative information through an intercalibration with landing proportions. This approach allowed us to reconstruct and quantitatively analyze a 200-year-long time series of fish community structure indicators in the Northern Adriatic Sea (Mediterranean Sea). Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species. This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources. To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

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Temporal trends of fish community structure indicators in the period 1800–1950 (N = 255 species).(a) Chondrichthyes; (b) large demersals; (c) species with a maximum body length between 120 and 250 cm; (d) species that reach sexual maturity within the 1st year of life.
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pone-0015502-g004: Temporal trends of fish community structure indicators in the period 1800–1950 (N = 255 species).(a) Chondrichthyes; (b) large demersals; (c) species with a maximum body length between 120 and 250 cm; (d) species that reach sexual maturity within the 1st year of life.

Mentions: A significant decline in the proportion of Chondrichthyes in the fish community from 17.3% to 11.4% was observed (β = −1.692, r2 = 0.627, p = 0.06; Figure 4a). Large demersals proportion significantly declined from 27% to 20.4% (β = −1.671, r2 = 0.577, p = 0.079; Figure 4b) and large-sized species (maximum body length between 120 and 250 cm) significantly declined from 17.5% to 13% (β = −1.066, r2 = 0.65, p = 0.053; Figure 4c). Conversely, the proportion of small-sized species (maximum body length between 25 and 55 cm) and fast-maturing species (species that reach sexual maturity within the 1st year of life) in the community significantly increased from 11.7% to 28.2% (β = 4.276, r2 = 0.779, p = 0.02), and from 5.9% to 17.8% (β = 2.788, r2 = 0.799, p = 0.016; Figure 4d), respectively. The mean trophic level substantially did not change (Table S8).


Coding early naturalists' accounts into long-term fish community changes in the Adriatic Sea (1800-2000).

Fortibuoni T, Libralato S, Raicevich S, Giovanardi O, Solidoro C - PLoS ONE (2010)

Temporal trends of fish community structure indicators in the period 1800–1950 (N = 255 species).(a) Chondrichthyes; (b) large demersals; (c) species with a maximum body length between 120 and 250 cm; (d) species that reach sexual maturity within the 1st year of life.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2984504&req=5

pone-0015502-g004: Temporal trends of fish community structure indicators in the period 1800–1950 (N = 255 species).(a) Chondrichthyes; (b) large demersals; (c) species with a maximum body length between 120 and 250 cm; (d) species that reach sexual maturity within the 1st year of life.
Mentions: A significant decline in the proportion of Chondrichthyes in the fish community from 17.3% to 11.4% was observed (β = −1.692, r2 = 0.627, p = 0.06; Figure 4a). Large demersals proportion significantly declined from 27% to 20.4% (β = −1.671, r2 = 0.577, p = 0.079; Figure 4b) and large-sized species (maximum body length between 120 and 250 cm) significantly declined from 17.5% to 13% (β = −1.066, r2 = 0.65, p = 0.053; Figure 4c). Conversely, the proportion of small-sized species (maximum body length between 25 and 55 cm) and fast-maturing species (species that reach sexual maturity within the 1st year of life) in the community significantly increased from 11.7% to 28.2% (β = 4.276, r2 = 0.779, p = 0.02), and from 5.9% to 17.8% (β = 2.788, r2 = 0.799, p = 0.016; Figure 4d), respectively. The mean trophic level substantially did not change (Table S8).

Bottom Line: Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species.This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources.To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

View Article: PubMed Central - PubMed

Affiliation: Department of Oceanography, Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Sgonico, Italy. tfortibuoni@ogs.trieste.it

ABSTRACT
The understanding of fish communities' changes over the past centuries has important implications for conservation policy and marine resource management. However, reconstructing these changes is difficult because information on marine communities before the second half of the 20(th) century is, in most cases, anecdotal and merely qualitative. Therefore, historical qualitative records and modern quantitative data are not directly comparable, and their integration for long-term analyses is not straightforward. We developed a methodology that allows the coding of qualitative information provided by early naturalists into semi-quantitative information through an intercalibration with landing proportions. This approach allowed us to reconstruct and quantitatively analyze a 200-year-long time series of fish community structure indicators in the Northern Adriatic Sea (Mediterranean Sea). Our analysis provides evidence of long-term changes in fish community structure, including the decline of Chondrichthyes, large-sized and late-maturing species. This work highlights the importance of broadening the time-frame through which we look at marine ecosystem changes and provides a methodology to exploit, in a quantitative framework, historical qualitative sources. To the purpose, naturalists' eyewitness accounts proved to be useful for extending the analysis on fish community back in the past, well before the onset of field-based monitoring programs.

Show MeSH