scholarly journals Proposed approaches to systematic planning of research and monitoring to support a South African inland fisheries policy

Water SA ◽  
2021 ◽  
Vol 47 (3 July) ◽  
Author(s):  
S Hugo ◽  
OLF Weyl
Keyword(s):  
Land Use ◽  
South African ◽  
Catch Per Unit Effort ◽  
Inland Fisheries ◽  
Model Based ◽  
Human Land Use ◽  
Unit Effort ◽  
Fisheries Policy ◽  
Systematic Planning

A South African inland fisheries policy will depend on a reliable long-term supply of social-ecological data covering freshwater fisheries at a broad geographic scale. Approaches to systematic planning of research and monitoring are demonstrated herein, based on a fishery-independent gillnet dataset covering 44 dams, and geographic information system maps of monthly and annual climate variables, human land use, and road access in a 5 km zone around 442 dams. Generalised linear mixed models were used to determine the covariates of gillnet catch per unit effort. Such covariates are required for a model-based process to select a subset of state-owned dams for a long-term fishery survey programme. The models indicated a monthly climate influence on catch per unit effort and climatic drivers of fish species distributions. However, unexplained variation is overwhelming and precludes a model-based survey design process. Non-hierarchical clustering of 442 dams was then done based on annual climate and human land use variables around dams. The resulting clusters of dams with shared climate and land use characteristics indicates the types of dams that should be selected for monitoring to represent the full range of climate and land use characteristics. Surrounding land use could indicate the socioeconomic characteristics of fisheries, for example, dams that may support subsistence-based communities that require increased research effort. Finally, although primary catchments could be useful for organising national-scale management, land use cover in the 5 km zone around dams varied widely within the respective primary catchments. Beyond these proposed approaches to plan research, this study also reveals various data deficiencies and recommends additional future studies on other possible methods for systematic research planning.

scholarly journals Benefits of water-related ecological infrastructure investments to support sustainable land-use: a review of evidence from critically water-stressed catchments in South Africa

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Alanna J. Rebelo ◽  
Petra B. Holden ◽  
Karen Esler ◽  
Mark G. New
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
South African ◽  
Evidence Base ◽  
Sustainable Land Use ◽  
Financial Investment ◽  
Ecological Infrastructure ◽  
Catchment Areas ◽  
Infrastructure Investments

Investments to promote sustainable land-use within critical river catchment areas are often undertaken to provide benefits to society. Investments generally aim to protect or restore ecological infrastructure—the underlying framework of ecosystems, functions and processes that supply ecosystem services—for multiple benefits to society. However, the empirical evidence base from studies across the world on both mechanisms and outcomes to support these assumptions is limited. We collate evidence on the benefits of ecological infrastructure interventions, in terms of ecosystem services provided to society, from three major South African water-providing catchments using a novel framework. In these catchments, millions of US Dollars' worth of investments have been made into ecological infrastructure since 1996. We ask the question: is there evidence that ecological infrastructure interventions are delivering the proposed benefits? Results show that even in catchments with substantial, long-term financial investment into ecological infrastructure, research has not empirically confirmed the benefits. Better baseline data collection is required, and monitoring during and after ecological infrastructure interventions, to quantify benefits to society. This evidence is needed to leverage investment into ecological infrastructure interventions at scale. Investment at scale is needed to transition to more sustainable land-use to unlock greater benefits to nature and people.

scholarly journals Reliability of a model based on a short fishery statistics survey: application to the Northeast Atlantic monkfish fishery

2004 ◽  
Vol 61 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Francisco Rocha ◽  
Joaquín Gracia ◽  
Ángel F González ◽  
Carlos M Jardón ◽  
Ángel Guerra
Keyword(s):  
Fishing Ground ◽  
Total Catch ◽  
Market Information ◽  
Catch Per Unit Effort ◽  
Northeast Atlantic ◽  
Model Based ◽  
Fish Market ◽  
Unit Effort

Abstract A model based on a short fishery statistics survey was applied to estimate catch and catch per unit effort (cpue) of the Galician monkfish (Lophius spp.) trawl fleet during 1998. In all, 35 interviews were conducted with fisheries personnel in ICES Divisions IXa, VIIIc, VIIId, and VIIIe (coastal offshore fishing grounds) and 44 in VIIb, VIIc, VIIj, and VIIk (Grand Sole fishing ground). Reliability of the model estimates was tested using: (i) registered fish market landings at 38 ports; (ii) landings data from sale invoices at six of these ports (93.8% of total landings of the species); (iii) 29 observers' trips made on board coastal offshore trawlers and the logbook of one Grand Sole trawler. Estimated mean total catch from the model was 5110 t (602 t coastal offshore, 4508 t in Grand Sole) and cpue values were 36.2 kg haul−1 vessel−1 coastal offshore and 104.4 kg haul−1 vessel−1 Grand Sole. Differences between the values of cpue estimated by the model and those determined directly in both fisheries were not significant. However, there were differences between the total catch estimated by the model and the total landings deduced from sale invoices and Galician fish market information.

scholarly journals Human Land-Use Practices Lead to Global Long-Term Increases in Photosynthetic Capacity

2014 ◽  
Vol 6 (6) ◽  
pp. 5717-5731 ◽  
Author(s):  
Thomas Mueller ◽  
Gunnar Dressler ◽  
Compton Tucker ◽  
Jorge Pinzon ◽  
Peter Leimgruber ◽  
...  
Keyword(s):  
Land Use ◽  
Photosynthetic Capacity ◽  
Human Land Use ◽  
Land Use Practices

scholarly journals Stable Isotopic Evidence for Nutrient Rejuvenation and Long-Term Resilience on Tikopia Island (Southeast Solomon Islands)

2021 ◽  
Vol 13 (15) ◽  
pp. 8567
Author(s):  
Jillian A. Swift ◽  
Patrick V. Kirch ◽  
Jana Ilgner ◽  
Samantha Brown ◽  
Mary Lucas ◽  
...  
Keyword(s):  
Land Use ◽  
Nutrient Dynamics ◽  
Solomon Islands ◽  
Isotope Analysis ◽  
Nutrient Status ◽  
Nitrogen Isotope ◽  
External Support ◽  
Deep Time ◽  
Human Land Use

Tikopia Island, a small and relatively isolated Polynesian Outlier in the Southeast Solomon Islands, supports a remarkably dense human population with minimal external support. Examining long-term trends in human land use on Tikopia through archaeological datasets spanning nearly 3000 years presents an opportunity to investigate pathways to long-term sustainability in a tropical island setting. Here, we trace nutrient dynamics across Tikopia’s three pre-European contact phases (Kiki, Sinapupu, Tuakamali) via stable carbon and nitrogen isotope analysis of commensal Pacific rat (Rattus exulans) and domestic pig (Sus scrofa) bone and tooth dentine collagen. Our results show a decline in δ15N values from the Kiki (c. 800 BC-AD 100) to Sinapupu (c. AD 100–1200) phases, consistent with long-term commensal isotope trends observed on other Polynesian islands. However, increased δ15N coupled with lower δ13C values in the Tuakamali Phase (c. AD 1200–1800) point to a later nutrient rejuvenation, likely tied to dramatic transformations in agriculture and land use at the Sinapupu-Tuakamali transition. This study offers new, quantifiable evidence for deep-time land and resource management decisions on Tikopia and subsequent impacts on island nutrient status and long-term sustainability.

scholarly journals Anthropogenic impact on biogenic Si pools in temperate soils

2011 ◽  
Vol 8 (3) ◽  
pp. 4391-4419 ◽  
Author(s):  
W. Clymans ◽  
E. Struyf ◽  
G. Govers ◽  
F. Vandevenne ◽  
D. J. Conley
Keyword(s):  
Land Use ◽  
Agricultural Development ◽  
Land Use Changes ◽  
Arable Land ◽  
Terrestrial Ecosystems ◽  
Human Land Use ◽  
Long Term Effect ◽  
Disturbed Land ◽  
The Impact

Abstract. Human land use changes directly affect silica (Si) mobilisation and Si storage in terrestrial ecosystems and influence Si export from the continents, although the magnitudes of the impact are unknown. Yet biogenic silica (BSi) in soils is an understudied aspect. We have quantified and compared total biogenic (PSia) and easily soluble (PSie) Si pools at four sites along a gradient of disturbance in southern Sweden. An estimate of the magnitude of change in temperate continental BSi pools due to human disturbance is provided. Land use clearly affects BSi pools and their distribution. Total PSia and PSie for a continuous forested site at Siggaboda Nature Reserve (66 900 ± 22 800 kg SiO2 ha−1 and 952 ± 16 kg SiO2 ha−1) are significantly higher than disturbed land use types from the Råshult Culture Reserve including arable land (28 800 ± 7200 kg SiO2 ha−1 and 239 ± 91 kg SiO2 ha−1), pasture sites (27 300 ± 5980 kg SiO2 ha−1 and 370 ± 129 kg SiO2 ha−1) and grazed forest (23 600 ± 6370 kg SiO2 ha−1 and 346 ± 123 kg SiO2 ha−1). Vertical PSia and PSie profiles show significant (p<0.05) variation among the sites. These differences in size and distribution are interpreted as the long-term effect of reduced BSi replenishment and increased mobilisation of the PSia in disturbed soils. In temperate regions, total PSia showed a 10 % decline since agricultural development (3000BCE). Recent agricultural expansion (after 1700CE) has resulted in an average export of 1.1 ± 0.8 Tmol Si yr−1, leading to an annual contribution of ca. 20 % to the global land-ocean Si flux carried by rivers. Human activities clearly exert a long-term influence on Si cycling in soils and contribute significantly to the land-ocean Si flux.

A National Prediction Model Based on Universal Kriging and Land-Use Regression Using Satellite- Based NO2 Measurements for Epidemiological Analysis of Long-Term Health Effects

2014 ◽  
Vol 2014 (1) ◽  
pp. 2627
Author(s):  
Michael T. Young* ◽  
Matthew J. Bechle ◽  
Paul D. Sampson ◽  
Julian D. Marshall ◽  
Lianne A. Sheppard ◽  
...  
Keyword(s):  
Land Use ◽  
Prediction Model ◽  
Health Effects ◽  
Universal Kriging ◽  
Land Use Regression ◽  
Epidemiological Analysis ◽  
Model Based

scholarly journals Two Thousand Years of Land-Use and Vegetation Evolution in the Andean Highlands of Northern Chile Inferred from Pollen and Charcoal Analyses

Quaternary ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 32 ◽  
Author(s):  
Alejandra Domic ◽  
José Capriles ◽  
Katerine Escobar-Torrez ◽  
Calogero Santoro ◽  
Antonio Maldonado
Keyword(s):  
Land Use ◽  
Environmental Changes ◽  
Management Strategies ◽  
Northern Chile ◽  
Human Land Use ◽  
Climatic Drivers ◽  
Land Use And Management ◽  
Andean Highlands ◽  
The Last Two Millennia

The European conquest of the New World produced major socio-environmental reorganization in the Americas, but for many specific regions and ecosystems, we still do not understand how these changes occurred within a broader temporal framework. In this paper, we reconstruct the long-term environmental and vegetation changes experienced by high-altitude wetlands of the southcentral Andes over the last two millennia. Pollen and charcoal analyses of a 5.5-m-long core recovered from the semi-arid puna of northern Chile indicate that while climatic drivers influenced vegetation turnaround, human land use and management strategies significantly affected long-term changes. Our results indicate that the puna vegetation mostly dominated by grasslands and some peatland taxa stabilized during the late Holocene, xerophytic shrubs expanded during extremely dry events, and peatland vegetation persisted in relation to landscape-scale management strategies by Andean pastoralist societies. Environmental changes produced during the post-conquest period included the introduction of exotic taxa, such as clovers, associated with the translocation of exotic herding animals (sheep, cattle, and donkeys) and a deterioration in the management of highland wetlands.

Land use, water and Mediterranean landscapes: modelling long-term dynamics of complex socio-ecological systems

2010 ◽  
Vol 368 (1931) ◽  
pp. 5275-5297 ◽  
Author(s):  
C. Michael Barton ◽  
Isaac I. Ullah ◽  
Sean Bergin
Keyword(s):  
Land Use ◽  
Spatial Scales ◽  
Computational Modelling ◽  
Ecological Systems ◽  
Land Use Land Cover ◽  
Human Land Use ◽  
Complex Interactions ◽  
Mediterranean Landscapes ◽  
Temporal And Spatial

The evolution of Mediterranean landscapes during the Holocene has been increasingly governed by the complex interactions of water and human land use. Different land-use practices change the amount of water flowing across the surface and infiltrating the soil, and change water’s ability to move surface sediments. Conversely, water amplifies the impacts of human land use and extends the ecological footprint of human activities far beyond the borders of towns and fields. Advances in computational modelling offer new tools to study the complex feedbacks between land use, land cover, topography and surface water. The Mediterranean Landscape Dynamics project (MedLand) is building a modelling laboratory where experiments can be carried out on the long-term impacts of agropastoral land use, and whose results can be tested against the archaeological record. These computational experiments are providing new insights into the socio-ecological consequences of human decisions at varying temporal and spatial scales.

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