Appendix
This Appendix mainly list the data estimated for the 1970s model. Detailed information for the 2000s model could be found in Li et al., 2009.
A.1. Parameterizations for the model
Average bottom temperature is 16.39 degree centigrade. Average surface temperature is 17.39 degree centigrade. Average is 16.89 degree centigrade, mainly for Q/B estimates of the benthopelagic fishes. Average depth and total area of East China Sea Shelf used for parameterizations was 72m and 500500 km2 (Zheng et al. 2003). We used the same temperature value for these two models.
A.1.1. Phytoplankton
Phytoplankton communities in the ECSS were dominated by diatoms (over 99% in numbers during a survey in the middle1950s), following by dinoflagellates and other groups (Gu et al. 1987; Zheng et al. 2003).
P/B ratio and biomass of phytoplankton in the 1970s model was obtained from published literature Gu et al. (1987).
A.1.2. Benthic producer
Benthic producer consists of benthic algae. Biomass and P/B ratio were based on the values reported in Pauly and Christensen (1995), i.e, 7.83tkm-2 and 11.9year-1. Since we found no evidence of large changes in biomass of this group over the past few decades, we assumed that the biomass and P/B ratio were the same in the 1970s and 2000s models.
Time series catch data was estimated from the national landings statistics from Zhejiang, Jiangsu and Fujian provinces in 2000 for both the models.
A.1.3. Detritus
Rough estimates of the standing stock of detritus in marine ecosystems may be obtained from:
Where D is the standing stock of detritus, in gCm-2, PP the primary production in gCm-2year-1, and E is the euphotic depth in meters (Pauly and Christensen 1993). In the absence of a readily available estimates of mean euphotic depth for ECSS, the detritus standing stock estimated by this equation for the South China Sea, of 100tkm-2 (Cheung 2007). The precise value of this estimate has no effect on the computation of detritus flows.Bacteria (incl. bacterioplankton) are not included in the model: it is assumed that bacteria consume only detritus, and that the fluxes associated with this consumption can be treated as if they occurred in another, adjacent ecosystem, i.e., that in which detritus accumulates when it leaves ECSS. This omission of bacterial fluxes has no impact whatsoever on the other estimates of fluxes estimated by Ecopath.
A.1.4. Zooplankton
Biomass of the 1970s model was obtained fromGu et al.(1987).The P/B and Q/B in the 1970s model was assumed to be the same with the value in the 2000s model (Li et al. 2009).
A.1.5. Jellyfish
The jellyfish group consists of medusae of the phylum Cnidaria. Local estimates for P/B and Q/B ratios are not available. Thus estimates from the Gulf of Daya (P/B=5.011year-1, Q/B= 25.05year-1)- the closest region where estimates were available. The biomass was estimated by Ecopath using the EE equaled to 0.95.
Catches were based on national landings statistics from Zhejiang, Jiangsu and Fujian provinces of 0.0085 tkm-2(Chinese Bureau of Fishery 2000).
Trophic data was obtained from Xiong et al.(2009).
A.1.6. Benthos
Benthos is sub-divided into five functional groups: polychaetes, echinoderms, benthic crustaceans, mollusks and other invertebrates. Biomass in the 1970s model were obtained from the survey carried out in June 1971. Local estimates on P/B and Q/B ratio for these groups were not available, thus I used estimates from other similar ecosystems (Table A1). The P/B and Q/B value were assumed to be constant during the time period. Catch estimates from the Sea Around Us Project catch database was used. Trophic data was obtained from other ecopath model (Optiz 1996).
TableA1. P/B and Q/B ratio from other similar ecosystemsFunctional groups / Parameters / Value / Sources
Polychaetes / P/B (year-1) / 6.7 / Xu et al. 2005
Q/B (year-1) / 24.2 / Opitz 1996
Echinoderms / P/B (year-1) / 1.2 / Opitz 1996
Q/B (year-1) / 3.7 / Pauly and Christense1993
Benthic crustaceans / P/B (year-1) / 6.56 / Pitcher et al. 1998
Q/B (year-1) / 26.9 / Opitz 1996
Catch / 0.042 / Sea Around Us database
Molluscs / P/B (year-1) / 3 / Christensen and Walters 2004
Q/B (year-1) / 7 / Opitz 1996
Catch / 0.308 / Sea Around Us Project database
Other invertebrates / P/B (year-1) / 1 / Opitz 1996
Q/B (year-1) / 9 / Opitz 1996
A.1.7. Shrimp
This group consists of Solenocera koelbeli, Trachypenaeus curvirostris, Parapenaeopsis hardwickii, Solenocera crassicornis,and Penaeus japonicas, etc. The biomass of shrimps was left to be estimated by the model by assuming EE equaled to 0.95. P/B ratio was based on the averaged total mortality estimates of Trachypenaeus curvirostris (3.6year-1) (3.1-4.1year-1). Q/B ratio of penaeid shrimps was based on the estimates available from Okey et al. (2004). Landing of shrimps in the 1970s model was obtained from the statistical report of SAUP.
Trophic data was borrowed from Daya Bay ecosystem (Wang et al., 2005).
A.1.8. Crabs
This group consists of Portunus trituberculatus, P. sanguinplentus, Ovalipes punctatus, Charybdis feriatus, and C.miles, C.japonica, C.riversandersoni and also the lobsters.Biomass was obtained from the survey took place in June 1971 (Gu et al. 1987). P/B and Q/B ratio were assumed to be similar to the South China Sea during the same period (3 year-1 and 12year-1, respectively) (Cheung 2007). Landing of crabs in the 1970s model was obtained from the statistical report of SAUP.
Trophic data was borrowed from Daya Bay ecosystem (Wang et al. 2005).
A.1.9. Cephalopods
In ECSS, Loligo squid was the dominant group of cephalopod, consisting of Loligo edulis and Loligo chinensis. Estimated logilo squid biomass in the 1970s model was estimated by CPUE ratio to be 1.282 t km-2. P/B ratio were assumed to be similar to the South China Sea during the same period (3.1year-1 and 8.0year-1 respectively) (Cheung 2007).
The catch estimates of the ECSS of both the time periods were obtained from the database of Sea Around Us Project, which amounted to 0.417t km-2(2000s) and 0.192 t km-2(1970s).
Trophic information was obtained from Zhang et al. (2003).
A.1.10. Threadfin bream (nemipterids)
This group consists of fish from the family Nemipteridae, including Nemipterus virgatus, N. bathybius and N. japonicus. Biomass in the 1970s model was estimated by CPUE to be 0.559 tkm-2. P/B ratio was assumed to be the total mortality rate, was estimated to be 3.08 year-1.
Catch data in the 2000s model was obtained from national landing statistics to be 0.32 t km-2, while in the 1970s was obtained from the Fujian landing statistics to be 0.0725 t km-2.
Trophic data was obtained from Zhang and Tang (2004).
A.1.11. Bigeyes (Priacanthids)
Bigeyes consist of fishes from the family Priacanthidae, mainly dominated by Priacanthus macracanthus. The biomass estimated in the 1970s model was obtained from Gu et al. (1987). P/B ratio was assumed to be similar to the Northern South China Sea Shelf ecosystem during the same period (2.74year-1) (Sun and Qiu 2004).Natural mortality rate was estimated from Pauly’s empirical equation (Pauly 1980). (F=1.87; M=0.87). Q/B ratio was estimated from the empirical equation (Palomares and Pauly 1998), to be 9.16year-1. Catch data was obtained from national landing statistics to be 0.0178 t km-2.
Trophic data was obtained from Wei and Huang (1992).
A.1.12. Lizarfish (Synodontids)
Fishes of the family Synodontids are included in this group. The major species in the ECSS include Saurida undosquamis Saurida elongate, Harpadon nehereus, Saurida wanieso, Saurida elongate, Synodus macrops and Trachinocephalus myops.Biomass of this group in the 1970s model was calculated using CPUE ratio. The P/B and Q/B values in the 1970s model were estimated using length and weight data, to be 2.1 and 7.0, respectively. Catch data was obtained from National landing statistics to be 0.00398 t km-2.
Trophic information was obtained from Zhang et al. (2003), Xue (2005).
A.1.13. Hairtails (Trichiurids)
This group is composed of fishes from the family Trichiuridae. This group has been seriously over-exploited and is now dominated by juvenile fishes (73.82% at age 1 or less) (Zheng et al. 2003). We segregated this group into two multi-stanza groups- juvenile (age 1 or less) and adult using multi-stanza routine in Ecopath (Christensen et al. 2005). In the late 1990s, biomass of Trichiurus lepturus- a dominant species of this group in the ECSS- from acoustic and trawl surveys in the late 1990s were estimated to be 0.659 t km-2 and 0.096 t km-2 the average was 0.378t km-2 by trawl survey (Zheng et al. 2003). Since catch of T. lepturus was mainly composed of juvenile fish, we allocated the entire estimated biomass to the juvenile stage, and we used the multi-stanza routine to estimate the adult stage biomass. P/B and Q/B ratios for the juvenile were assumed to be similar to the South China Sea during the same period (3.08year-1 and 14.9year-1, respectively). P/B ratio for the adult group was estimated to be 2.9year-1 using the B-H model. Q/B ratio was estimated to be 10.5year-1 from an empirical equation (Palomares and Pauly 1998).
Landing of hairtail reported in the national statistics in 2000 was 294559t based on the Sea Around Us Project database. Since the majority of the hairtails caught in the 2000s were reported to be juveniles (1<year) which take up to 73.82% of the total biomass (Zheng et al. 2003), the biomass of juvenile and adult were 0.282 t km-2and 0.101t km-2, respectively.
Biomass of hairtails in the 1970s was obtained from Gu et al. (1987)to 0.916 t km-2, by analyzing the age structure in the 1970s, the biomass of the adult and juvenile group represented 83.5% and 16.5% of the total biomass. The P/B and Q/B ratios were estimated using empirical equations (Palomares and Pauly1998).
Trophic information was obtained from Wei (1980)andZhang et al. (2003).
A.1.14. Pomfrets (Stromateids)
Members of this group are fish from the family Stromateidae, mainly dominated by Pampus cinereus and Pampus argenteus. Estimated pomfrets biomassesof the 1970s were estimated to be 3.963 t km-2 based on the coastal survey in Jiangsu Province in 1970.P/B ratio was estimated to be 1.28year-1 (Lin et al. 2006). (Estimates of total mortality or exploitation rates were mainly available for demersal or pelagic species, but not benthopelagic species. Thus P/B ratios were left to be estimated by the model, assuming P/Q ratio of 0.2 (Christensen et al. 2005)). Q/B ratio was estimated to be 6.40year-1 from an empirical equation (Palomares and Pauly 1998). Catch data was obtained from the national landing statistics (0.192t km-2).
Trophic information was obtained fromDadzie et al. (2000)andXue (2005).
A.1.15. Snappers
Members of this group are from the family Lujanidae, including Lutjanus Argentimaculatus and Lutjanus Vaigiensis. The biomass of the 1970s model was not available and was estimated by assuming EE=0.95. P/B ratio was obtained from Gu et al. (1987) to be 1.30 year-1.Q/B ratio was estimatedto be 8.98year-1 from an empirical equation (Palomares and Pauly1998). Catch data was obtained from the National landing statistics (0.00071 tkm-2).
Trophic information was obtained from Yang (2001) and Zhang and Tang (2004).
A.1.16. Groupers
Members of this group are from the family Serranidae. Biomass estimates were not available and thus they were estimated in the models by assuming EE to be 0.95. Natural mortality rate was estimated to be 0.67 year-1 from Pauly’s empirical equation. P/B ratio was obtained from Gu et al. (1987) to be 1.24 year-1. Q/B ratio was estimatedto be 6.27year-1 from an empirical equation (Palomares and Pauly 1998). Catch data was obtained from the National landing statistics (0.0313 tkm-2).
Trophic information was obtained fromYang (2001) and Zhang and Tang (2004).
A.1.17. Small croakers
Members of this group are from the family Sciaenidae, with total length less than or equal to 30 cm. Commercially important species include Argyrosomus Spp. and Pennahia spp. The biomass of the 1970s model was not available and was estimate by assuming EE=0.95. P/B ratio was estimated using the available data in 1980-1983 to be 1.36 year-1. Q/B ratio was estimated to be 12.0 year-1 from the empirical equation (Palomares and Pauly 1998). Catch data was obtained from the national statistics to be 0.102 tkm-2.
Trophic information was obtained from Xue (2005), Lin (2007)andWang (2008).
A.1.18. Large croakers
Large croakers are Sciaenidae with maximum total length of more than 30cm. This group was seriously over-explored, and is currently composed of mostly juveniles (more than 90% in landings) (Zheng et al. 2003), including the mainly commercially important species Larimichthys crocea and Larimichthys polyactis. The biomass in the 1970s model was obtained to be 1.050 year-1from Guet al. (1987). The P/B ratio was estimated using F+M (F=0.94, M=0.11) (Gu et al. 1987). Q/B ratio was calculated to be 6.84 year-1using empirical equation of Palomares and Pauly (1998). Catch data was estimated using the data from Sea Around Us Project database.
Trophic information was obtained from Yang (2001).
A.1.19. Small benthopelagic fishes
This group consists of benthopelagic fish with maximum total length less than or equal to 30 cm. benthopelagic fish was defined as fish living and feeding near the bottom as well as in mid-water or near the surface ( estimates were not available and thus they were estimated in the models by assuming EE to be 0.95. P/B ratio was obtained from Gu et al. (1987) to be 1.72 year-1. Q/B ratio was estimated from a P/Q ratio of 0.3. Catch data was obtained from Sea Around Us Project database (0.242 tkm-2).
Trophic information was obtained from Zhang et al. (2003).
A.1.20. Large benthopelagic fishes
This group consists of benthopelagic fish with maximum total length more than 30cm. Biomass estimates were not available and thus they were estimated in the models by assuming EE to be 0.95. The biomass of the 1970s model was not available and was estimated by assuming EE=0.95. P/B ratio was obtained from Gu et al. (1987)to be 2.08 year-1. Q/B ratio was estimated from a P/Q ratio of 0.3. Catch data was obtained from Sea Around Us Project database (0.204 tkm-2).
Trophic data was borrowed from Zhang and Tang (2003).
A.1.21. Small pelagic fishes
This group consists of 18 species of pelagic fish with maximum total length less than or equal to 30 cm. In the late 1990s, total biomass of commercially important small pelagic fish, including sardine, thryssa, anchovy, etc. The biomass of the 1970s model was obtained from the survey in 1972, and was estimated to be 2.912 t km-2. P/B ratio was obtained from Gu et al. (1987) to be 3.9 year-1. Q/B ratio was estimated from the empirical equation (Palomares and Pauly 1998) based on the survey data, to be 17.04year-1. Catch data was obtained from Sea Around Us Project database (0.268 tkm-2).
Trophic data of the anchovy (Engraulis japonicas and Thrissa kammalensis) were used to represent this group. The information was obtained from Guo and Tang (2000), Huang (2004), Xue (2005)andGuo et al. (2007).
A.1.22. Large pelagic fishes
This group consists of pelagic fish with maximum total length greater than 30cm (except those species that have been included in other functional groups). The biomass of the 1970s model was obtained from the survey in 1972. P/B and Q/B ratios of the 1970s werenot available, thus, we used the value of the 2000s model. P/B was estimated to be 1.37year-1 (Lin et al. 2006). Catch data was obtained from Sea Around Us Project database (0.04 tkm-2).
Trophic data was borrowed fromZhang et al. (2003)andXue (2005).
A.1.23. Sharks and rays
Elasmobranchs were divided into demersal and pelagic groups. Demersal sharks and rays represented about 0.5% of the bottom trawler’s catches in the late 1990s (Zhang 2005). This was assumed to represent the relative abundance of demersal elasmobranchs relative to total demersal biomass during the same period. Thus biomass was estimated to be about 0.003 km-2. However, this biomass level was found to be too low to support the fishery. Pelagic sharks and rays were ill-presented in demersal trawlers. Thus the biomass of pelagic sharks and rays were left to be estimated by the model by assuming EE of 0.95. P/B and Q/B for both groups were obtained from the NSCS models during the same period (Cheung 2007).
Biomass of the 1970s model was calculated to be 0.0082 t km-2 using the CPUE ratio. The P/B and Q/B ratios were assumed to be constant.Landings were obtained based on the SAUP database to 0.0162 t km-2
Trophic data was borrowed from Wang et al. (1996)andZhang (2005).
A.1.24. Seabirds, marine turtles and marine mammals
Since the parameters for these groups were not available for the whole modeled region, the input parameters values were assumed to be the same as the ecosystem models of NSCS (Cheung 2007).
Trophic data was obtained from Karpouzi (2001).
A.1.25. Flatfishes
Members of this group are fish from the family Bothidae, Paralichthyidae and Soleidae. Based on the acoustic survey in the late 1990s, the estimated total biomass of the dominated species Pleuronichthys cornutus, Crossorhombus azureus and Cynoglossus robustus was 0.022 t km-2 (Zheng et al. 2003). The biomass of the 1970s model was not available and was estimated by assuming EE=0.95. The P/B ratio was assumed to be constant during the period. The average natural mortality was approximately 1.4 year-1. Exploitation rate (q) in the 2000s was estimated to be about 0.8 for demersal fishes (Zheng et al. 2003). Thus total mortality rate was approximately 1.75 year-1. Q/B ratio was estimated to be 8.75year-1 by assuming the P/Q ratio of 0.3. Catch data was obtained from the SAUP database (0.0834 tkm-2).
Trophic data was obtained fromCheung (2007).
A.1.26. Small reef-associated fishes
This group consists of reef-associated fish with maximum total length less than or equal to 30 cm (except those species that have been included in other functional groups). The commercially valuable species were mainly from the family Cantherhines and Serranidae. Biomass estimates were not available and thus they were estimated in the models by assuming EE to be 0.95. P/B was estimated to be 1.92year-1 (Optiz 1996). Q/B was estimated to be 7.97year-1 from the empirical equation (Palomares and Pauly 1998). Catch data was obtained from the SAUP database (0.0213 tkm-2).
Trophic information was obtained from Zhang and Tang (2004).
A.1.27. Large reef-associated fishes
This group consists of reef-associated fish with maximum total length greater than 30cm (except those species that have been included in other functional groups). Biomass estimates were not available and thus they were estimated in the models by assuming EE to be 0.95. P/B was estimated to be 0.38year-1 (Optiz 1996). Q/B was estimated to be 3.9year-1 from the empirical equation (Palomares and Pauly 1998). Catch data was obtained from the SAUP database (0.00071 tkm-2).
Trophic information was obtained from Zhang and Tang (2004).
A.1.28. Demersal fishes
Demersal fish 1 consists of 34 different species based on the results of Cluster analysis (Check Li et al., 2009 for details). P/B value for demersal fish 1 was estimated to be 3.4year-1 using Z=F+M; M= empirical equation from Pauly (1980). Q/B ratio was obtained from empirical equation (Palomares and Pauly 1998). Biomasses were estimated from trawling survey (1998-2001) in the East China Sea Shelf (Zheng et al. 2003) to be 0.13t km-2. Catch data were obtained from the SAUP database to be 0.02 t km-2. Demersal fish 2 consists of 32 different species based on the results of Cluster analysis. P/B value for demersal fish 2 was estimated to be 4.2 year-1 using Z=F+M; M= empirical equation from Pauly(1980). Q/B ratio was obtained from empirical equation (Palomares and Pauly 1998). Biomass was estimated from trawling survey (1998-2001) in the East China Sea Shelf (Zheng et al. 2003) to be 0.312t km-2. Catch data were obtained from the SAUP database to be 0.43 t km-2. Demersal fish 3 consists of 24 different species. Biomass estimates were not available and thus were left to be estimated by the model by assuming EE of 0.95. P/B and Q/B for both groups were obtained from the NSCS models during the same period (Cheung 2007). Catch data were obtained from the national statistics and SAUP database.