DOI: 10.5281/zenodo.16601929
title: Carbon fluxes, net burial and landings in the Celtic Sea (outputs derived from StrathE2E model)

description: This dataset includes carbon fluxes computed by postprocessing nitrogen outputs from StrathE2E model runs, by taking into account carbon-nitrogen stoichiometry dynamics in the food web.

This dataset was compiled for deliverable 5.2 of the Ocean-ICU Horizon Europe project.

Version 1.1 updates:



The algorithm had minor errors which were fixed.

Quality improved observational data used for fitting and optimising parameter q.


StrathE2E model runs

The StrathE2E model is an end-to-end ecosystem model, describing the entire food web within shelf regions, from inorganic nutrients to megafauna (Heath et al, 2021). It uses climate model outputs, and combined with a fishing fleet model, StrathE2E allows for the study of both climate and fishing effects on nutrient cycling and trophic interactions.

Data were computed from running the following StrathE2E model variants and fishing scenarios:




Region
Period
Climate input
Climate scenario
Fishing (yes/no)
Notes


Celtic Sea
2010-2019
CNRM
SSP1-2.6
yes
 


Celtic Sea
2010-2019
CNRM
SSP1-2.6
no
 


Celtic Sea
2040-2049
CNRM
SSP1-2.6
yes
 


Celtic Sea
2040-2049
CNRM
SSP1-2.6
no
 


Celtic Sea
2010-2019
CNRM
SSP3-7.0
yes
baseline model


Celtic Sea
2010-2019
CNRM
SSP3-7.0
no
 


Celtic Sea
2040-2049
CNRM
SSP3-7.0
yes
 


Celtic Sea
2040-2049
CNRM
SSP3-7.0
no
 


Celtic Sea
2010-2019
GFDL
SSP1-2.6
yes
 


Celtic Sea
2010-2019
GFDL
SSP1-2.6
no
 


Celtic Sea
2040-2049
GFDL
SSP1-2.6
yes
 


Celtic Sea
2040-2049
GFDL
SSP1-2.6
no
 


Celtic Sea
2010-2019
GFDL
SSP3-7.0
yes
baseline model


Celtic Sea
2010-2019
GFDL
SSP3-7.0
no
 


Celtic Sea
2040-2049
GFDL
SSP3-7.0
yes
 


Celtic Sea
2040-2049
GFDL
SSP3-7.0
no
 




Dataset description

Overview

For each model variant and fishing scenario tested, the following data (in .csv format) are available:



Carbon budget data ("#_Cbudget-data.csv")

Matrices of annual carbon and nitrogen fluxes for whole area (inshore and offshore zones combined) from last year model outputs ("#_C-fluxes.csv" and "#_N-fluxes.csv")

Landings by guild (e.g. planktivorous fish, pelagic invertebrates, benthos, birds...) and by gear (e.g. beam trawls, dredges...) in carbon and nitrogen units ("#_C-land-by-gear.csv" and "#_N-land-by-gear.csv")


In addition, the "CN-ratios_all-model-variants.csv" file compiles all resulting C:N ratios of each guild for each model run performed here.

Carbon budget data

This contains a summary of the following boundary and internal (production) fluxes which are of interest for the deliverable 5.2 of the Ocean-ICU project:



Carbon sequestration (net sediment burial)

Landings

Discards

Corpses (note that discards end up in this guild after a short life time (see flux matrices))

Faecal pellets

CO2 absorption by food web guilds

CO2 release by food web guilds

Beach cast of macrophytes (kelp)

Passive inflow of organic carbon (from phytoplankton and detritus) from open ocean

Passive outflow of organic carbon (from phytoplankton and detritus) from open ocean

Fish migration inflow

Fish migration outflow


For each variable, both the total annual flux and flux by guild are given.

Matrices of annual carbon and nitrogen fluxes

Each column represent the destination/consumer guild and each row the source/prey guild.

Example: the value read in row "carnzoo" (carnivorous zooplankton) and column "pfish" (planktivorous fish) is the annual flux of consumption of carnivorous zooplankton by planktivorous fish.

These matrices include boundary fluxes (e.g. open ocean, atmosphere...).

Fluxes are given in mmol.m^(-2).y^(-1) of either carbon or nitrogen.

Landings by guild and by gear

Units: mmol.m^(-2).y^(-1) of carbon/nitrogen

Fishing gears:



artisanal

beam trawls

dredges

driftings and handlines

fly dragging and anchor seine

gillnets and longlines

kelp harvesting

mid-water trawl

nephrops trawls

pots

purse seine.


Guilds harvested:



Planktivorous fish

Quota-limited demersal fish

Non-quota demersal fish

Migratory fish

Suspension/deposit feeding benthos

Carnivore/scavenge feeding benthos

Pelagic invertebrates

Birds

Pinnipeds

Cetaceans

Macrophytes


C:N ratios

Table compiling C:N molar ratios by guild for each model variant.

Note: These C:N ratios are the result of a nitrogen-to-carbon conversion which describes the transfer of carbon up the food web by using one parameter (q). This parameter was fitted to compiled observational C:N ratio data using outputs from the baseline model (so one parameter value for model variant with CNRM climate input and one for model with GFDL). Once fitted, this parameter value was kept constant for all other model runs.

Funding acknowedgement

This work was co-funded by the European Union under grant agreement no. 101083922 (OceanICU) and UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant number 10054454, 10063673, 10064020, 10059241, 10079684, 10059012, 10048179]. The views, opinions and practices used to produce this dataset are however those of the author(s) only and do not necessarily reflect those of the European Union or European Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.