Temporal trends in abundance and body size of coastal fish communities in Galicia: recovering the lost original baseline ____________________________________________________ Pablo Pita & Juan Freire II International Symposium in Marine Science. Vigo, April 27-30, 2009

Introduction Global overfishing scenario. ____________________________________________________ Pablo Pita & Juan Freire - General consensus. - Catches don't vary. - Fishing down and through. - Effort increases. - Shifting baseline syndrome. - What fall (if exists)?. FAO, 2008

Global overfishing scenario.

Global overfishing scenario. The FEGAS archive. - Non profit organization. - 4000 spearfishers. - Spearfishers championships since 1953. - Recorded recreational competitions in a given time and area. ____________________________________________________ Pablo Pita & Juan Freire

Global overfishing scenario.

The FEGAS archive.

- Non profit organization.

- 4000 spearfishers.

- Spearfishers championships since 1953.

- Recorded recreational competitions in a given time and area.

Global overfishing scenario. The FEGAS archive. Lucky us!: long term database. High certainty level of catches. Constant catchability and fishing areas. ____________________________________________________ Pablo Pita & Juan Freire 900 championships. 13000 cases. Uninterrupted since 1953. Techniques constant. Same spots. CPUE proportional to abundance.

Global overfishing scenario.

The FEGAS archive.

Lucky us!: long term database. High certainty level of catches. Constant catchability and fishing areas.

900 championships.

13000 cases.

Uninterrupted since 1953.

Techniques constant.

Same spots.

CPUE proportional to abundance.

Methods Long-term trends (1953-2007) in coastal fish communities using GLM. - Analyzing 50 years by GLM. - The model: Catch or body size = a + b1· year + b2· effort (h) + b3. effort (n) + b4· scope + b5· discipline + b6· month + b7. area - Dependant variables: Catch number, catch weight and body size (weight). - Explanatory variables: Year (1953-2007), effort (h), effort (spearfishers n), scope (National to local), discipline (individual, couples, teams), month (1-12) and area (5). - Effort as explanatory similar to CPUE analysis. - AIC to select best model. ____________________________________________________ Pablo Pita & Juan Freire

Long-term trends (1953-2007) in coastal fish communities using GLM.

- Analyzing 50 years by GLM.

- The model:

Catch or body size = a + b1· year + b2· effort (h) + b3. effort (n) + b4· scope + b5· discipline + b6· month + b7. area

- Dependant variables: Catch number, catch weight and body size (weight).

- Explanatory variables: Year (1953-2007), effort (h), effort (spearfishers n), scope (National to local), discipline (individual, couples, teams), month (1-12) and area (5).

- Effort as explanatory similar to CPUE analysis.

- AIC to select best model.

Results Catch number, catch weight and body size averages. ____________________________________________________ Pablo Pita & Juan Freire Catch number 5.2 ind. (SE ±0.06)

Catch number, catch weight and body size averages.

Catch number

Catch number, catch weight and body size averages. ____________________________________________________ Pablo Pita & Juan Freire 7.2 kg (SE ± 0.09)

Catch number, catch weight and body size averages.

Catch number, catch weight and body size averages. ____________________________________________________ Pablo Pita & Juan Freire 1.9 kg (SE ± 0.01)

Catch number, catch weight and body size averages.

Temporal trends: catch number, catch weight and body size. ____________________________________________________ Pablo Pita & Juan Freire

Temporal trends: catch number, catch weight and body size.

Temporal trends: catch number , catch weight and body size. ____________________________________________________ Pablo Pita & Juan Freire

Temporal trends: catch number , catch weight and body size.

Temporal trends: catch number , catch weight and body size. ____________________________________________________ Pablo Pita & Juan Freire -44%

Temporal trends: catch number , catch weight and body size.

Temporal trends: catch number, catch weight and body size. ____________________________________________________ Pablo Pita & Juan Freire

Temporal trends: catch number, catch weight and body size.

Temporal trends: catch number, catch weight and body size. ____________________________________________________ Pablo Pita & Juan Freire -74%

Temporal trends: catch number, catch weight and body size.

Temporal trends: catch number, catch weight and body size . ____________________________________________________ Pablo Pita & Juan Freire

Temporal trends: catch number, catch weight and body size .

Temporal trends: catch number, catch weight and body size . ____________________________________________________ Pablo Pita & Juan Freire -35%

Temporal trends: catch number, catch weight and body size .

Temporal trends: catch number, catch weight and body size per species . ____________________________________________________ Pablo Pita & Juan Freire -6% -43%

Temporal trends: catch number, catch weight and body size per species .

Conclusions The number of fishes has been reduced by 44%. The biomass of coastal fishes has been reduced by 74%. Fishes are a 35% smaller. These are nearly-collapse symptoms of coastal waters. ____________________________________________________ Pablo Pita & Juan Freire

The number of fishes has been reduced by 44%.

The biomass of coastal fishes has been reduced by 74%.

Fishes are a 35% smaller.

These are nearly-collapse symptoms of coastal waters.

____________________________________________________ Thank you Pablo Pita & Juan Freire II International Symposium in Marine Science. Vigo, April 27-30, 2009