Demographic Modelling in the Analysis of Population Dynamics of Deep-Sea Macrobenthos

Wildlife sanctuaries rescue, rehabilitate, reintroduce and provide life-long care for orphaned and injured animals. Understanding a sanctuary’s population dynamics—patterns in arrival, mortality and projected changes in population size—allows careful planning for future needs. Building on previous work on the population dynamics of chimpanzees (Pan troglodytes) in sanctuaries of the Pan African Sanctuary Alliance (PASA; Faust et al. 2011), this chapter extends analyses to the only PASA bonobo sanctuary. Its authors analysed historic demographic patterns and projected future population dynamics using an individual-based demographic model. The population has been growing at 6.7 per cent per year, driven by arrivals of new individuals (mean = 5.5 arrivals per year). Several model scenarios projecting varying arrival rates, releases and breeding scenarios clarify potential future growth trajectories for the sanctuary. This research illustrates how data on historic dynamics can be modelled to inform future sanctuary capacity and management needs. Les sanctuaires de faune secourent, réhabilitent, réintroduisent, et fournissent des soins pour toute la vie aux animaux orphelins et blessés. Comprendre les dynamiques de la population d’un sanctuaire—les motifs d’arrivée, mortalité, et de changements projetés de la taille de la population—permet une planification prudente pour les nécessités du futur. En se basant sur le travail déjà fait sur les dynamiques de la population chimpanzé (Pan troglodytes) dans les sanctuaires du Pan African Sanctuary Alliance (PASA; Faust et al. 2011), nous étendons notre analyse au seul sanctuaire bonobo par PASA. Nous avons analysé les motifs démographiques historiques et avons projeté les futures dynamiques de la population en utilisant un modèle démographique basé sur l’individu. La population augmente de 6.7 per cent par an, poussée par l’arrivée de nouveaux individus (moyenne = 5.5 arrivées par an). Plusieurs scénarios modèles montrent une trajectoire de potentielle croissance pour le sanctuaire. Cette recherche illustre comment modeler les données sur les dynamiques historiques pour informer la capacité future du sanctuaire et les besoins gestionnaires.

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Interannual variation in the epibenthic megafauna at the shallowest station of the HAUSGARTEN observatory (79° N, 6° E)

Biogeosciences Discussions ◽

10.5194/bgd-9-18039-2012 ◽

2012 ◽

Vol 9 (12) ◽

pp. 18039-18081 ◽

Cited By ~ 1

Author(s):

K. S. Meyer ◽

M. Bergmann ◽

T. Soltwedel

Keyword(s):

Population Dynamics ◽

Deep Sea ◽

Interannual Variation ◽

Suspension Feeding ◽

Fram Strait ◽

Population Densities ◽

Camera System ◽

Sea Floor ◽

Time Period ◽

Food Input

Abstract. Epibenthic megafauna play an important role in the deep-sea environment and contribute significantly to benthic biomass, but their population dynamics are still understudied. We used a towed deep-sea camera system to assess the population densities of epibenthic megafauna in 2002, 2007 and 2012 at the shallowest station (HG I, ~ 1300 m) of the deep-sea observatory HAUSGARTEN, in the eastern Fram Strait. Our results indicate that the overall density of megafauna was significantly lower in 2007 than in 2002, but was significantly higher in 2012, resulting in overall greater megafaunal density in 2012. Different species showed different patterns in population density, but the relative proportions of predator/scavengers and suspension-feeding individuals were both higher in 2012. Variations in megafaunal densities and proportions are likely due to variation in food input to the sea floor, which decreased slightly in the years preceding 2007 and was greatly elevated in the years preceding 2012. Both average evenness and diversity increased over the time period studied, which indicates that HG I may be food-limited and subject to bottom-up control. The varying dynamics of different species may have been caused by differential capacities of populations to respond to increased food input through either recruitment or migration.

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The role and status of Nautilus in its natural habitat: evidence from deep-water remote camera photosequences

Paleobiology ◽

10.1017/s0094837300008472 ◽

1984 ◽

Vol 10 (4) ◽

pp. 469-486 ◽

Cited By ~ 37

Author(s):

W. Bruce Saunders

Keyword(s):

Growth Rate ◽

Population Dynamics ◽

Deep Water ◽

Deep Sea ◽

Natural Habitat ◽

Normal Component ◽

Depth Range ◽

Reproductive Tactics ◽

Opportunistic Predator ◽

Remote Camera

Bottom site remote camera photosequences at depths of 73–538 m on forereef slopes in Palau show that Nautilus belauensis is a highly mobile, chemosensitive, epibenthic scavenger and opportunistic predator. The overall depth range of this species is ca. 70–500 m, but photosequences indicate a preferred range of 150–300 m. Nautilus is active both nocturnally and diurnally, locating bait sites within 1–2 h. Associated macrofauna includes caridean shrimps, crabs, and eels; teleosts are rare below 100 m, but sharks are recorded in most photosequences below 250 m. Summarily, Nautilus exhibits a combination of characters that typify deep-sea strategy, including reproductive tactics, growth rate, and population dynamics. This and other evidence suggest that fossil Nautilidae may have been deep-water forms, in contrast to the typically shallower water ammonoids, and that Nautilus is a normal component of the deep forereef rather than a late Cretaceous refugee from shallow water.

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Interannual variation in the epibenthic megafauna at the shallowest station of the HAUSGARTEN observatory (79° N, 6° E)

Biogeosciences ◽

10.5194/bg-10-3479-2013 ◽

2013 ◽

Vol 10 (6) ◽

pp. 3479-3492 ◽

Cited By ~ 20

Author(s):

K. S. Meyer ◽

M. Bergmann ◽

T. Soltwedel

Keyword(s):

Population Dynamics ◽

Deep Sea ◽

Interannual Variation ◽

Suspension Feeding ◽

Fram Strait ◽

Population Densities ◽

Camera System ◽

Sea Floor ◽

Time Period ◽

Food Input

Abstract. Epibenthic megafauna play an important role in the deep-sea environment and contribute significantly to benthic biomass, but their population dynamics are still understudied. We used a towed deep-sea camera system to assess the population densities of epibenthic megafauna in 2002, 2007, and 2012 at the shallowest station (HG I, ∼1300 m) of the deep-sea observatory HAUSGARTEN, in the eastern Fram Strait. Our results indicate that the overall density of megafauna was significantly lower in 2007 than in 2002, but was significantly higher in 2012, resulting in overall greater megafaunal density in 2012. Different species showed different patterns in population density, but the relative proportions of predator/scavengers and suspension-feeding individuals were both higher in 2012. Variations in megafaunal densities and proportions are likely due to variation in food input to the sea floor, which decreased slightly in the years preceding 2007 and was greatly elevated in the years preceding 2012. Both average evenness and diversity increased over the time period studied, which indicates that HG I may be food-limited and subject to bottom-up control. The community of HG I may be unique in its response to elevated food input, which resulted in higher evenness and diversity in 2012.

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Drivers of demography: past challenges and a promise for a changed future

10.1093/oso/9780198838609.003.0006 ◽

2021 ◽

pp. 115-130

Author(s):

Pedro F. Quintana-Ascencio ◽

Eric S. Menges ◽

Geoffrey S. Cook ◽

Johan Ehrlén ◽

Michelle E. Afkhami

Keyword(s):

Population Dynamics ◽

Environmental Variables ◽

Environmental Drivers ◽

Factors Affecting ◽

Future Developments ◽

Projections And Predictions ◽

Demographic Modelling ◽

Experimental Approaches ◽

Closed Systems ◽

Metapopulation Models

There is an urgent need to understand how populations and metapopulations respond to shifts in the environment to mitigate the consequences of human actions and global change. Identifying environmental variables/factors affecting population dynamics and the nature of their impacts is fundamental to improve projections and predictions. This chapter examines how environmental drivers, both continuous (stress) and episodic (disturbance), are incorporated in demographic modelling across many types of organisms and environments, using both observational and experimental approaches to characterise drivers. It critically summarises examples of the main approaches and identifies major accomplishments, challenges, and limitations. The chapter points to promising approaches and possible future developments. In the initial sections, models in closed systems without migration among populations are considered. The chapter then focuses on metapopulation models, emphasising the importance of understanding drivers affecting migration and differential extinction among populations. Finally, it concludes with a discussion of some important and general problems associated with assessing how population dynamics may be affected by environmental drivers that are dynamic, nonlinear, and with indirect and/or interacting effects with other drivers..

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