scholarly journals Challenges of transferring models of fish abundance between coral reefs

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4566 ◽  
Author(s):  
Ana M.M. Sequeira ◽  
Camille Mellin ◽  
Hector M. Lozano-Montes ◽  
Jessica J. Meeuwig ◽  
Mathew A. Vanderklift ◽  
...  
Keyword(s):  
Predictive Models ◽  
Fishing Effort ◽  
Fish Abundance ◽  
Target System ◽  
Fish Family ◽  
Topographic Complexity ◽  
Total Fish ◽  
Spatio Temporal ◽  
Improved Performance ◽  
Fish Abundances

Reliable abundance estimates for species are fundamental in ecology, fisheries, and conservation. Consequently, predictive models able to provide reliable estimates for un- or poorly-surveyed locations would prove a valuable tool for management. Based on commonly used environmental and physical predictors, we developed predictive models of total fish abundance and of abundance by fish family for ten representative taxonomic families for the Great Barrier Reef (GBR) using multiple temporal scenarios. We then tested if models developed for the GBR (reference system) could predict fish abundances at Ningaloo Reef (NR; target system), i.e., if these GBR models could be successfully transferred to NR. Models of abundance by fish family resulted in improved performance (e.g., 44.1% <R2 < 50.6% for Acanthuridae) compared to total fish abundance (9% <R2 < 18.6%). However, in contrast with previous transferability obtained for similar models for fish species richness from the GBR to NR, transferability for these fish abundance models was poor. When compared with observations of fish abundance collected in NR, our transferability results had low validation scores (R2 < 6%,p > 0.05). High spatio-temporal variability of patterns in fish abundance at the family and population levels in both reef systems likely affected the transferability of these models. Inclusion of additional predictors with potential direct effects on abundance, such as local fishing effort or topographic complexity, may improve transferability of fish abundance models. However, observations of these local-scale predictors are often not available, and might thereby hinder studies on model transferability and its usefulness for conservation planning and management.

No-trawl area impacts: perceptions, compliance and fish abundances

2012 ◽  
Vol 39 (3) ◽  
pp. 237-247 ◽  
Author(s):  
H.J. BLOOMFIELD ◽  
C.J. SWEETING ◽  
A.C. MILL ◽  
S.M. STEAD ◽  
N.V.C. POLUNIN
Keyword(s):  
High Mobility ◽  
Fishing Effort ◽  
Fish Abundance ◽  
Management Tool ◽  
Small Areas ◽  
Abundance Data ◽  
Mobile Species ◽  
Baited Traps ◽  
Fish Abundances ◽  
Size Data

SUMMARYMPAs are being established worldwide at an increasing rate, however empirical evidence for benefits to mobile species of small areas closed to fishing in temperate regions are little known. Using two North Sea prohibited trawling areas (PTAs) established > 80 years ago, social (fishers’ perceptions), management (fishing effort and compliance) and ecological (fish abundance and size) data were combined to assess the PTAs against their primary societal (conflict resolution) and secondary ecological (stock protection) objectives. Fishers perceived that the PTAs resolved conflicts between static and mobile gear sectors, despite evidence of non-compliance. However, few fishers perceived that they personally benefited from the PTAs. Fish abundance and size data from baited traps (BT) and video (BV) provided no evidence of PTA effects, but trawling effort was a significant predictor of BT fish abundance data and improved the model of BV fish abundance data. The absence of PTA effects on fish is attributable to non-compliance, the high mobility of the fish involved and their continued exploitation within the PTAs using static gear. This points to the need for greater understanding of the behaviour of fishers in relation to closures. The study also highlights the challenges of quantifying possible fishery benefits of small temperate closed areas and questions whether widely advocated fishery benefits may have enhanced initial support, but failure to deliver them may erode faith in such closures as a fisheries management tool.

scholarly journals Climate drivers of plague epidemiology in British India, 1898–1949

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200538
Author(s):  
Warren S. D. Tennant ◽  
Mike J. Tildesley ◽  
Simon E. F. Spencer ◽  
Matt J. Keeling
Keyword(s):  
Predictive Models ◽  
Control Measures ◽  
Climate Data ◽  
British India ◽  
Middle Income ◽  
Middle Income Countries ◽  
Complex Interactions ◽  
The World ◽  
Spatio Temporal

Plague, caused by Yersinia pestis infection, continues to threaten low- and middle-income countries throughout the world. The complex interactions between rodents and fleas with their respective environments challenge our understanding of human plague epidemiology. Historical long-term datasets of reported plague cases offer a unique opportunity to elucidate the effects of climate on plague outbreaks in detail. Here, we analyse monthly plague deaths and climate data from 25 provinces in British India from 1898 to 1949 to generate insights into the influence of temperature, rainfall and humidity on the occurrence, severity and timing of plague outbreaks. We find that moderate relative humidity levels of between 60% and 80% were strongly associated with outbreaks. Using wavelet analysis, we determine that the nationwide spread of plague was driven by changes in humidity, where, on average, a one-month delay in the onset of rising humidity translated into a one-month delay in the timing of plague outbreaks. This work can inform modern spatio-temporal predictive models for the disease and aid in the development of early-warning strategies for the deployment of prophylactic treatments and other control measures.

scholarly journals Study on Fish Ecology of the Seti Gandaki River Pokhara: II. Spatio-Temporal Variations in Fish Communities

2012 ◽  
Vol 12 ◽  
pp. 350-357 ◽  
Author(s):  
KK Pokharel
Keyword(s):  
Winter Season ◽  
Temporal Variations ◽  
Urban Site ◽  
Total Density ◽  
Brachydanio Rerio ◽  
Upstream Site ◽  
Longitudinal Pattern ◽  
Total Fish ◽  
Spatio Temporal ◽  
Pokhara Valley

Present paper deals with the spatio-temporal variations in distribution and abundance of fishes along the 30 km stretch of the Seti Gandaki river and its two major tributaries, Mardi Khola and Vijaypur Khola, in Pokhara Valley, Western Nepal. A total of 30 species of fishes belonging to 5 orders, 9 families and 22 genera were recorded from five sites on the river and its tributaries. Cyprinoids were predominant among fishes (17 spp.), siluroids (5 spp.), balitorids and cobitids (4 spp.), channioids (2 spp.), belonoids (one sp.) and mastacembeloids (one sp.). Among cyprinoids, mostly cyprinines were dominant groups (7 spp.) followed by rasborines (7 spp.), garrines (2 spp.) and schizothoracines (one sp.). There was increasing trend of species richness at upstream site (17 spp.). to downstream site (20 spp.) showing a longitudinal pattern. The total fish abundance and family-wise abundance at all the sites observed major peak during the spring and fall during the winter season in both the years of study. The average total density of fishes during the spring peak was highest (51.07/ha) at the upper tributary site and lowest (24.69/ha) at the urban site. According to the distribution pattern and abundance, the population status of the gamefish, mahseer [Tor tor (Ham)] has been endangered (E); that of game fishes [Tor putitora (Ham.) and Chagunius chagunio (Ham.)] and Zebra-fish [Brachydanio rerio (Ham.)] to are vulnerable (V); that of loach [Lepidocephalus guntea (Ham.)], cat-fishes [Myersglanis blythii (Day) and Amblyceps mangois (Ham.)] are rare (R).DOI: http://dx.doi.org/10.3126/njst.v12i0.6523 Nepal Journal of Science and Technology 12 (2011) 350-357

Spatio-Temporal Just Noticeable Distortion Model Guided Video Watermarking

2010 ◽  
Vol 2 (4) ◽  
pp. 16-36
Author(s):  
Yaqing Niu ◽  
Sridhar Krishnan ◽  
Qin Zhang
Keyword(s):  
Video Watermarking ◽  
Original Video ◽  
Temporal Modulation ◽  
Visual Model ◽  
Visual Models ◽  
Dct Domain ◽  
Just Noticeable Distortion ◽  
Spatio Temporal ◽  
Improved Performance ◽  
Watermarking Scheme

Perceptual Watermarking should take full advantage of the results from human visual system (HVS) studies. Just noticeable distortion (JND), which refers to the maximum distortion that the HVS does not perceive, gives a way to model the HVS accurately. An effective Spatio-Temporal JND model guided video watermarking scheme in DCT domain is proposed in this paper. The watermarking scheme is based on the design of an additional accurate JND visual model which incorporates spatial Contrast Sensitivity Function (CSF), temporal modulation factor, retinal velocity, luminance adaptation and contrast masking. The proposed watermarking scheme, where the JND model is fully used to determine scene-adaptive upper bounds on watermark insertion, allows providing the maximum strength transparent watermark. Experimental results confirm the improved performance of the Spatio-Temporal JND model. The authors’ Spatio-Temporal JND model is capable of yielding higher injected-watermark energy without introducing noticeable distortion to the original video sequences and outperforms the relevant existing visual models. Simulation results show that the proposed Spatio-Temporal JND model guided video watermarking scheme is more robust than other algorithms based on the relevant existing perceptual models while retaining the watermark transparency.

scholarly journals Spatial and temporal changes in fish yields and fish communities in the largest tropical floodplain lake in Asia

2017 ◽  
Vol 53 ◽  
pp. 485-493 ◽  
Author(s):  
Bunyeth Chan ◽  
Peng Bun Ngor ◽  
Nam So ◽  
Sovan Lek
Keyword(s):  
Functional Groups ◽  
Fish Species ◽  
Temporal Changes ◽  
Pangasianodon Hypophthalmus ◽  
Tonle Sap ◽  
Commercial Species ◽  
Fish Catch ◽  
Total Fish ◽  
Spatio Temporal ◽  
Fish Yields

Although the Tonle Sap Lake is the largest natural inland lake in Southeast Asia, little is known about the spatio-temporal patterns of its composition and yields. The present paper aimed to investigate the temporal change of yields of the most dominant fish species and to evaluate the spatio-temporal changes in the fish community and the indicator species of assemblages. Fish catch data were collected from thirty-three fishing lots around the lake during the open season from October to May each year between 1994 and 2000. The fish yields were dominated by few commercial fishes: Channa micropeltes, Pangasianodon hypophthalmus, Channa striata, Cyclocheilichthys enoplos, Henicorhynchus spp., Barbonymus gonionotus, Micronema spp. and Trichopodus microlepis. The standard linear regression coefficients of the fish yields versus year were negative for all these commercial species except T. microlepis. Moreover, the total fish yields of the lake were temporally declined (standard coefficient = −2.410, adjusted r2 = 0.272). Nonmetric multidimensional scaling of the fish assemblage data showed a clear opposition between northern assemblage and southern assemblage along the first axis, and the temporal pattern of the samples from 1994 to 1999 was explained by the second axis. The fish species assemblage from earlier years (1994 and 1995) was characterised by the abundance of all functional groups of black-white-grey fish species, but more recent years (1996–1999) were linked to white and grey functional groups, which was explained by a decrease in many black fishes.

scholarly journals Overlooked biological and economic implications of within-season fishery dynamics

2014 ◽  
Vol 71 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Xiaozi Liu ◽  
Mikko Heino
Keyword(s):  
Concentration Profile ◽  
Fishing Effort ◽  
Economic Consequences ◽  
Fish Abundance ◽  
Fishing Pressure ◽  
Fishing Mortality ◽  
Economic Implications ◽  
Special Cases ◽  
Total Stock ◽  
Stock Abundance

Catch equations relate fisheries catch to initial fish abundance and the applied fishing pressure. The Baranov catch equation, often simply referred to as the catch equation, is the commonest one. However, there are exactly three ways of describing seasonal progression of fishing parsimoniously with a single parameter: assume catch rate, fishing effort, or fishing mortality is constant, the last being the assumption underlying the Baranov catch equation. These assumptions imply different dynamics, and only in special cases two of these assumptions can hold true simultaneously. Whether this happens is dictated by the concentration profile (i.e., the dependence of mean fish density where fishing takes place on total stock abundance). We show that the assumed seasonal progression of fishing and the type of the concentration profile have major implications for fishery dynamics as well as biological and economic consequences of fishing, calling for increased awareness of these overlooked assumptions of fishery dynamics. However, in many cases the Baranov catch equation serves as a good approximation, even when its assumption of constant fishing mortality is violated.

Comparative cleaning behaviour of Pederson's cleaner shrimp (Ancylomenes pedersoni) between geographically close yet ecologically dissimilar coral reef habitats

2020 ◽  
Vol 100 (7) ◽  
pp. 1093-1106
Author(s):  
Joseph J. Romain ◽  
Dan A. Exton ◽  
David J. Smith ◽  
Amelia Rose ◽  
Clayton Vondriska ◽  
...  
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Fish Population ◽  
Fish Abundance ◽  
Environmental Drivers ◽  
Variable Nature ◽  
Total Fish ◽  
Abundance And Diversity ◽  
Lutjanus Apodus ◽  
Cleaner Shrimp

AbstractCleaning mutualisms are important interactions on coral reefs. Intraspecific variation in cleaning rate and behaviour occurs geographically and is often attributed to local processes. However, our understanding of fine-scale variation is limited, but would allow us to control for geography and region-specific behavioural patterns. Here, we compare the cleaning activity of Pederson's cleaner shrimp (Ancylomenes pedersoni) on two neighbouring, yet ecologically dissimilar, reef systems in Honduras: Banco Capiro, an offshore bank close to significant land runoff with high coral cover but a depleted fish population, and an oligotrophic fringing reef around the island of Utila, with lower coral cover but high fish abundance and diversity. The proportion of realized to potential fish clientele was <60% at both sites, and the composition of clientele was neither reflective of the demographics of the resident assemblages at each site nor similar between sites. Parrotfishes represented 13–15% of total fish abundance at both sites yet accounted for >50% (Banco Capiro) and 10% (Utila) of all cleans. Conversely, the schoolmaster snapper (Lutjanus apodus) represented ~1% of total fish abundance at both sites yet accounted for 40% (Utila) and 1% (Banco Capiro) of all cleans. After standardizing our cleaning rate data by clientele abundance, we find that clientele at Banco Capiro engage in over four times as many cleaning encounters per hour with A. pedersoni than at Utila. Our study highlights the variable nature of coral reef cleaning interactions and the need to better understand the ecological and environmental drivers of this biogeographic variation.

scholarly journals Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

2013 ◽  
Vol 70 (3) ◽  
pp. 618-627 ◽  
Author(s):  
Morten Vinther ◽  
Margit Eero
Keyword(s):  
Fishing Effort ◽  
Fish Populations ◽  
Fishing Mortality ◽  
Fishing Impact ◽  
Management Measures ◽  
Stock Assessments ◽  
Spatio Temporal ◽  
Substantial Decline ◽  
The Impact ◽  
Temporal Overlap

Abstract Vinther, M., and Eero, M. 2013. Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density. – ICES Journal of Marine Science, 70: 618–627. Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may suffer from uncertain catch information and consequently lack reliable estimates of fishing mortality. In this study we develop an approach to obtain proxies for changes in fishing mortality based on effort information and predicted stock distribution. Cod in the Kattegat is used as an example. We use GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline in the impact of the Danish demersal trawl fleet on cod in the Kattegat in recent years, due to a combination of closed areas, introduction of selective gears and changes in overall effort.

scholarly journals Teaching basic numeracy, predictive models and socioeconomics to marine ecologists through Bayesian belief networks

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 312 ◽  
Author(s):  
Richard Stafford ◽  
Rachel Williams
Keyword(s):  
Predictive Models ◽  
Species Interactions ◽  
Rocky Shore ◽  
Marine Ecosystem ◽  
Predictive Modelling ◽  
Bayesian Belief Networks ◽  
Fishing Effort ◽  
Management Approach ◽  
Afternoon Session ◽  
Belief Network

Teaching numeric disciplines to higher education students in many life sciences disciplines is highly challenging. In this study, we test whether an approach linking field observations with predictive models can be useful in allowing students to understand basic numeracy and probability, as well as developing skills in modelling, understanding species interactions and even community/ecosystem-service interactions.  We presented a field-based lecture in a morning session (on rocky shore ecology), followed by an afternoon session parameterising a belief network using a simple, user-friendly interface. The study was conducted with students during their second week of a foundation degree, hence having little prior knowledge of these systems or models. All students could create realistic predictive models of competition, predation and grazing, although most initially failed to account for trophic cascade effects in parameterising their models of the rocky shore they had previously seen. The belief network was then modified to account for a marine ecosystem management approach, where fishing effort and economic benefit of fishing were linked to population abundance of different species, and management goals were included. Students had little difficultly in applying conceptual links between species and ecosystem services in the same manner as between species. Students evaluated their understanding of a range of variables from rocky shore knowledge to marine management as increasing over the session, but the role of the predictive modelling task was indicated as a major source of learning, even for topics we thought may be better learned in the field. The study adds evidence to the theories that students benefit from exposure to numeric topics, even very early in their degree programmes, but students grasp concepts better when applied to real world situations which they have experience of, or perceive as important.

scholarly journals Scottish Inshore Fisheries Integrated Data System (SIFIDS): work package (2) final report WP2A: development and pilot deployment of a prototypic autonomous fisheries data harvesting system, and WP2B: investigation into the availability and adaptability of novel technological approaches to data collection

2019 ◽  
Author(s):  
R. Ayers ◽  
G.P. Course ◽  
G.R. Pasco
Keyword(s):  
Data Collection ◽  
Economic Value ◽  
Fishing Effort ◽  
Final Report ◽  
Executive Summary ◽  
Fishing Activity ◽  
Business Decisions ◽  
Fishing Vessels ◽  
Spatio Temporal ◽  
Data Deficient

[Extract from Executive Summary] To enhance sustainability and foster resilience within Scotland’s inshore fishing communities an effective system of collecting and sharing relevant data is required. To support business decisions made by vessel owners as well as informing fisheries managers and those involved in marine planning it will be vital to collect a range of information which will provide a robust understanding of fishing activity, the economic value of the sector and its importance within local communities. The SIFIDS Project was conceived to assist in attaining these goals by working alongside fishers to develop and test technology to automatically collect and collate data on board vessels, thereby reducing the reporting burden on fishers. The project built upon previous research funded through the European Fisheries Fund (EFF) and was designed to deliver a step change in the way that inshore fisheries in Scotland could be managed in cooperation with the industry. The project focussed on inshore fishing vessels around Scotland, where spatio-temporal information on the distribution of vessels and associated fishing effort is data deficient. The whole project was broken down into 12 highly integrated work packages. This is the integrated report for work packages 2A and 2B, entitled’ Development and Pilot Deployment of a Prototypic Autonomous Fisheries Data Harvesting System’ (2A) and ‘Investigation into the Availability and Adaptability of Novel Technological Approaches to Data Collection’ (2B).

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