| Themes | DiscardLess Case studies Description |
| Name of the indicator | Where the selected species are mostly discarded inside the case studies for the third gear (in the list of Gears sorted by the discards values of each gear for the last available year of data). Selected species are those that are under quotas and that can become choke species. The selection allow to avoid take into account some species with high discards as the Gurnard because they are not targeted species (commercially not interesting) |
| Definition | Discards estimated by species and statistical rectangle for the case study in 2013. |
| Objectives | View how discards by species are spatially distributed inside the case study and for one major gear |
| View | |
| Calculation description |
We used the landings weigth given by statistical rectangle and the discards ratio at the regulated area level (for each species/vessel length/gear/country/year strata)
We sum the total values of discards by gears and we filter the data for the 3rd more important gear in terms of total discards.
Using discards ratio and landings we estimate a total discards for each rectangle / species for the specific year using calculation described in the presentation part of the website.
|
| Reading guide | For each rectangle you get the Discards weigth for each of the 5 first major species. Other, merge discards weight of other species. |
| Data sources |
Data used to produce figures comes from the STECF dissemination tool . Details on data can be found in the Fisheries Dependent Information working group report and from the Mediterranean and Black sea report |
| Comments | Please note that time series might be incomplete for some countries/indicators. |
| Query |
with part1 as
(
select distinct country,annexe,reg_area,reg_gear_cod,species,year_d,rectangle,english_name,reg_gear,sum(A.landings) as landings,sum(discards)/(sum(discards)+sum(B.landings)) as tx_discards
from landing_rect_sd A inner join discard_landings_sd B
using(country,annexe,reg_area,reg_gear_cod,species,year_d,vessel_length,reg_gear,specon) inner join cs_rectangles using(rectangle) left join asfis on (species=a_code)
inner join choke_species using(id_case,species)
where id_case=3 and country in ('ESP','FRA') and year_d=2015
and discards>0 group by reg_gear,country,annexe,reg_area,reg_gear_cod,species,year_d,rectangle,english_name order by year_d,sum(A.landings)
)
,part2 as
(
select country,annexe,reg_gear_cod,reg_gear,species,year_d,rectangle,english_name,landings,reg_area,case when tx_discards=1 then 0.99 else tx_discards end as tx_discards from part1
)
,part4 as
(
select distinct rectangle as LIEU,english_name as GROUPE,sum(((1/(1-tx_discards))*landings)-landings) as VAL,reg_gear from part2 left join countries using(country)
group by LIEU,GROUPE,reg_gear
)
,
selection_engin1 as
(
select reg_gear,sum(VAL) as VALTOT from part4 group by reg_gear order by VALTOT desc limit 1 offset 2
)
,total as
(select GROUPE,sum(VAL) as tot from part4 inner join selection_engin1 using(reg_gear) group by GROUPE order by tot DESC limit 6)
,regroupement as
(select distinct LIEU,case when total.GROUPE is null then 'Other' else GROUPE end as GROUPE,VAL as VAL,reg_gear
from part4 inner join selection_engin1 using(reg_gear) left join total using(GROUPE))
select distinct LIEU,GROUPE,sum(VAL) as VAL,reg_gear from regroupement group by LIEU,GROUPE,reg_gear
order by LIEU,GROUPE
|
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