Compartive network analyses for Nigerian coastal waters using two ecopath models developed for the years 1985 and 2000

Adebola, Tunde; Mutsert, Kim de

doi:10.1016/j.fishres.2018.12.028

Cited by 8 publications

(3 citation statements)

References 11 publications

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“…Similar studies that have been done in this field can be mentioned as Tajzadeh-Namin et al (2020) in the northern Sea of Oman, Behera et al (2020) in the Chilika Lagoon, Adebola and Mutsert (2019) in the inshore waters of Nigeria, Li et al (2019) in Zhushanhu's rehabilitated ecosystem of Tai Lake, Natugonza et al (2019) in the Victoria Lake ecosystem (East Africa), Hakimelahi (2018) Using the Ecopath software, the current study aimed to determine the ecosystem-based trophic structure of dominant commercial fishes in the Kolahi to Dargahan regions. The possibility of ecological management of fish stocks can be more precise and scientific while studying food relationships in an ecosystem impacted by human activities, especially fishing.…”

Section: Introductionsupporting

confidence: 75%

“…Similar studies that have been done in this field can be mentioned as Tajzadeh‐Namin et al (2020) in the northern Sea of Oman, Behera et al (2020) in the Chilika Lagoon, Adebola and Mutsert (2019) in the inshore waters of Nigeria, Li et al (2019) in Zhushanhu's rehabilitated ecosystem of Tai Lake, Natugonza et al (2019) in the Victoria Lake ecosystem (East Africa), Hakimelahi (2018) in the Persian Gulf, Dutta et al (2017) on the north shores of the Bay of Bengal in India, Razinkovas‐Baziukas et al (2017) in the Baltic Sea, Navarro et al (2017) in the northern Mediterranean, Behzadi (2016) in the Persian Gulf; Reinaldo et al (2016) in the San‐Matias Bay; Taghavi Motlagh et al (2015) in the Persian Gulf waters (Hormozgan, Bushehr, and Khuzestan); Webber et al (2015) in Foul and Folly Bays, Jamaica; and Taghavi Motlagh et al (2013) in the Persian Gulf (Hormozgan province).…”

Section: Introductionsupporting

confidence: 71%

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Trophic structure using ecological relationships between five dominant commercial fish in Kolahi to Dargahan

et al. 2023

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The purpose of this study was to determine the effects of frequent species population fluctuations and the impact of different rates of exploitation on other ecological links in the food web. The mass-balanced Ecopath model represents the trophic interactions among the 31 defined functional groups in the Kolahi to Dargahan area, with five main species, including Trichiurus lepturus, Saurida tumbil, Nemipterus japonicus, Sillago sihama, and Cynoglossus arel (from April 2018 to April 2019). To investigate the effects of fishing and environmental disturbances, the Ecopath modeling approach combines software for analyzing ecosystem trophic-level balances with population dynamic models. In the past 5 years, Hormozgan province has caught more than 45% of the benthic fish caught off the northern coasts of the Persian Gulf. From Kolahi to Dargahan, one of the most important fishing grounds in this province's southeast is located. Food web models are used to represent a marine system's current state, assess stock levels, and predict change over time. Over a year, the first five dominant fish in the study area, S. tumbil, S. sihama, C. arel, N. japonicus, and T. lepturus, were biometrically measured, and their population dynamics parameters as well as feeding ecology indices were analyzed. According to the trophic-level index results, the five most common species studied in this study belonged to the third (N. Japonicas, S. sihama, and C. arel) and fourth (T. lepturus, and S. tumbil) trophic levels. The key species with the greatest impact on other groups of studied species were identified as S. tumbil and T. lepturus, respectively. The estimated ecosystem indicators were the system operational power (75846.797), the primary production/respiration ratio (0.034), the connectance index (0.159), and the system omnivory index (0.253). A pedigree index (PI) of 0.38 was estimated for the present model. Overexploitation of T. lepturus could disrupt the aquatic food web and adversely affect the long-term sustainable use of aquatic resources, according to data. As a result, ecosystem-based fisheries management should be implemented to find a more appropriate solution to sustainable exploitation in the studied habitat, an important fishing area in the Persian Gulf's north.

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Section: Introductionsupporting

confidence: 75%

Section: Introductionsupporting

confidence: 71%

Trophic structure using ecological relationships between five dominant commercial fish in Kolahi to Dargahan

et al. 2023

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“…We used the 1985 NCW EwE model from Adebola and de Mutsert () (more details about the model and the data used in parameterizing it can be found in the Appendix ). Estimates of Pink Shrimp biomass and fisheries catch data (reconstruction data from Sea Around Us) were used to calibrate the model dynamically to evaluate predictive capability of the model in Ecosim where biomass dynamics are expressed as follows:

\frac{d B_{i}}{dt} = g_{i} {false\sum}_{j = 1}^{n} Q_{ji} (B_{j} (t), B_{i} (t)) - {false\sum}_{j = 1}^{n} Q_{ij} (B_{i} (t), B_{j} (t)) + I_{i} - (M 0_{i} (t) + F_{i} (t) + false(e_{i}) B_{i} (t) false)

where

B_{i} false(t false)

is the biomass of i at time t,

g_{i}

is the growth efficiency,

I_{i}

is the immigration rate;

M 0_{i}

is the natural mortality,

F_{i} false(t false)

is the fishing mortality,

e_{i}

is the emigration rate,

Q_{italicji}

represents the consumption due to predation on

i

by predator

j

, and

Q_{italicij}

represent the consumption due to predation on group

j

by predator

i

(Christensen and Walters ).…”

Section: Methodsmentioning

confidence: 99%

Spatial simulation of redistribution of fishing effort in Nigerian coastal waters using Ecospace

Adebola

Mutsert

2019

Ecosphere

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In the late 1990s, depletion of the target species Penaeus notialis (Pink Shrimp) in deeper waters (50 m) of the Nigerian coast resulted in a change of target species from P. notialis (Pink Shrimp) to shallower water species such as Penaeus monodon (Brown Shrimp). This study investigates the hypothesis that ecosystem impacts increased as industrial fleets increased fishing in shallower areas of the Nigerian coast by comparing the state of the ecosystem before and 20 yr after commercial shrimping commenced in Nigerian coastal waters (NCW). Two fishing scenarios were developed in Ecospace, the spatial modeling module of Ecopath with Ecosim software (Ecopath with Ecosim is a mass balanced trophic model that accounts for fishing impacts on food webs), with one having trawlers fishing everywhere beginning at the turn of the century (year 2000) and the other with no trawling in the first 5 nautical miles off the Nigerian coast through the entire period of model simulation (1985–2004). Modeling results showed increases in catch for some fisheries during the study period. In addition, estimated biomass for some functional groups increased especially for Small Pelagic fishes along with Rays, Reef fishes, Large Pelagics, and shallow water shrimps. All other exploited species in our modeling scenarios were estimated to have declining biomasses. Our expectation that redistribution of fishing effort in NCW will increase negative impacts of fishing the nearshore ecosystem was not supported by model results. This counterintuitive result may be because fishing effort on average was mostly distributed in the deeper areas of the inshore waters. Although specie such as Reef fishes appear to benefit from closure of the first 5 NM to fishing, the benefits appear to be negligible. We present the first ecosystem model developed for NCW, and our research contributes to fisheries ecology by furthering understanding of tropical coastal food webs and ecological response to fishing, especially in highly perturbed ecosystems like NCW.

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Comparison of three modelling frameworks for aquatic ecosystems: practical aspects and applicability

Patonai

Fábián

2022

COMMUNITY ECOLOGY

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Freshwater ecosystems are under multiple stressors and it is crucial to find methods to better describe, manage, and sustain aquatic ecosystems. Ecosystem modelling has become an important tool in integrating trophic relationships into food webs, assessing important nodes using network analysis, and making predictions via simulations. Fortunately, several modelling techniques exist, but the question is which approach is relevant and applicable when? In this study, we compare three modelling frameworks (Ecopath, Loop Analysis in R, STELLA software) using a case study of a small aquatic network (8 nodes). The choice of framework depends on the research question and data availability. We approach this topic from a methodological aspect by describing the data requirements and by comparing the applicability and limitations of each modelling approach. Each modelling framework has its specific focus, but some functionalities and outcomes can be compared. The predictions of Loop Analysis as compared to Ecopath’s Mixed Trophic Impact plot are in good agreement at the top and bottom trophic levels, but the middle trophic levels are less similar. This suggests that further comparisons are needed of networks of varying resolution and size. Generally, when data are limiting, Loop Analysis can provide qualitative predictions, while the other two methods provide quantitative results, yet rely on more data.

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Compartive network analyses for Nigerian coastal waters using two ecopath models developed for the years 1985 and 2000

Cited by 8 publications

References 11 publications

Trophic structure using ecological relationships between five dominant commercial fish in Kolahi to Dargahan

Trophic structure using ecological relationships between five dominant commercial fish in Kolahi to Dargahan

Spatial simulation of redistribution of fishing effort in Nigerian coastal waters using Ecospace

Comparison of three modelling frameworks for aquatic ecosystems: practical aspects and applicability

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