Robert B Thorpe

Centre for Environment, Fisheries and Aquaculture Science | CEFAS · Division of Fisheries

Zooplankton are the key intermediary between primary production and the fish community and a cornerstone of marine food webs, but they are often poorly represented in models that tend to focus on fish, charismatic top predators, or ocean biogeochemistry. In this study, we use an intermediate complexity end‐to‐end food web model of the North Sea wit...

The current epoch in fisheries science has been driven by continual advances in laboratory techniques and increasingly sophisticated approaches to analysing datasets. We now have the scientific knowledge and tools to proactively identify obstacles to the sustainable management of marine resources. However, in addition to technological advances, the...

Natural ecological communities exhibit complex mixtures of interspecific biological interactions, which makes finding optimal yet sustainable exploitation rates challenging. Most fisheries management advice is at present based on applying the Maximum Sustainable Yield (MSY) target to each species in a community by modelling it as if it was a monocu...

Ecosystem-based management is mandated by international legislation, including the Marine Strategy Framework Directive (MSFD) in the EU. This introduces a requirement for marine environments to achieve "Good Environmental Status" or GES, implying that the ecosystem is in a healthy and biodiverse state which does not limit the management options of...

Multispecies models have existed in a fisheries context since at least the 1970s, but despite much exploration, advancement, and consideration of multispecies models, there remain limited examples of their operational use in fishery management. Given that species and fleet interactions are inherently multispecies problems and the push towards ecosy...

ABSTRACT: The Mediterranean Rhodes gyre is a cyclonic gyre with high primary production due to local upwelling of nutrients, and occasional deep overturning up to 1km depth. This nutrient-rich state is in sharp contrast to other parts of the Eastern Mediterranean which are oligotrophic. Here we study the upwelling system central to the Rhodes gyre...

Understanding change at the base of the marine foodwebs is fundamental to understanding how climate change can impact fisheries. However, there is a shortage of empirical measurements of primary productivity, and models estimates often disagree with each other by an order of magnitude or more. In this study we incorporate information from empirical...

Achieving Good Environmental Status (GES) requires managing ecosystems subject to a variety of pressures such as climate change, eutrophication, and fishing. However, ecosystem models are generally much better at representing top-down impacts from fishing than bottom-up impacts due to warming or changes in nutrient loading. Bottom-up processes ofte...

To effectively implement ecosystem-based fisheries management, tools are needed that are capable of exploring the likely consequences of potential management action for the whole ecosystem. Quantitative modelling tools can be used to explore how ecosystems might respond to potential management measures, but no one model can reliably forecast all as...

Climate change is affecting large-scale oceanic processes. How and when these changes will impact those reliant on marine resources is not yet clear. Here we use end-to-end modeling to track the impacts of expected changes through the marine ecosystem on a specific, small community: Cochamó, in the Gulf of Ancud wider area, Chile. This area is impo...

Howell et al. 2021 have suggested a pathway to include multispecies/ecosystem considerations in the assessment process without changing the existing single species advice. This is a valuable step forward, but whilst doing this we need to guard against risks caused by a) incorrect attribution of ecosystem state, b) incommensurate fishing rates betw...

Fish communities are multispecies assemblages, so ideally multispecies models should be used directly for assessing this resource. However, progress in this direction has been slow, partly because these models are often more complex and take longer to fit, rendering them too slow to demonstrate near-real-time utility, and thus creating a perception...

Case studies in support of Caswell et al. 2020.

In marine management, fish stocks are often managed on a stock‐by‐stock basis using single‐species models. Many of these models are based upon statistical techniques and are good at assessing the current state and making short‐term predictions; however, as they do not model interactions between stocks, they lack predictive power on longer timescale...

This workshop is the third in a series of workshops on guidelines for developing Management Strategy Evaluations (MSEs) within ICES, and was intended to explore some of the issues that arose out of workshops that actually developed MSEs for a range of ICES stocks since the second MSE guidelines workshop was held in early 2019. It is intended that r...

In marine management, fish stocks are often managed on a stock-by-stock basis using single-species models. Many of these models are based upon statistical techniques and are good at assessing the current state and making short-term predictions; however, as they do not model interactions between stocks, they lack predictive power on longer timescale...

Climate change and fishing represent two of the most important stressors facing fish stocks. Forecasting the consequences of fishing scenarios has long been a central part of fisheries management. More recently, the effects of changing climate have been simulated alongside the effects of fishing to project their combined consequences for fish stock...

In 2018 we published a spatially-explicit individual-based model (IBM) that uses satellite-derived maps of food availability and temperature to predict Northeast Atlantic mackerel (Scomber scombrus, NEAM) population dynamics. Since then, to address various ecological questions, we have extended the IBM to include additional processes and data. Thro...

Fish are increasingly exposed to anthropogenic stressors from human developments and activities such as agriculture, urbanization, pollution and fishing. Lethal impacts of these stressors have been studied but the potential sublethal impacts, such as behavioural changes or reduced growth and reproduction, have often been overlooked. Unlike mortalit...

The concept of ‘blue growth’, which aims to promote the growth of ocean economies whilst holistically managing marine socio-ecological systems, is emerging within national and international marine policy. The concept is often promoted as being novel, however, we show that, historical analogies exist which can provide insights for contemporary plann...

Fish stocks interact through predation and competition for resources, yet stocks are typically managed independently on a stock-by-stock basis. The need to take account of multi-species interactions is widely acknowledged. However, examples of the application of multi-species models to support management decisions are limited as they are often seen...

Over recent years the summer feeding distribution of Northeast Atlantic mackerel (NEAM, Scomber scombrus) has expanded from its traditional core in the Norwegian Sea, northwards towards Svalbard, and westward as far as Greenland. Food availability, temperature and an increase in spawning stock biomass (SSB) are reported to be possible drivers of th...

The Workshop on the Development of Quantitative Assessment Methodologies based on Life-history traits, exploitation characteristics, and other relevant parameters for data-limited stocks (WKLIFE) focuses on the provision of sound advice rules for data-limited stock (DLS) assess-ments that are within the ICES MSY framework. This ninth workshop was c...

The concept of an optimum yield at intermediate levels of fishing (the so called maximum sustainable yield or MSY) has been with us since the 1930s and is now enshrined in legislation as a key objective of fisheries management. The concept seems intuitively reasonable and is readily applicable to a single stock treated in isolation and assuming a c...

Maximum sustainable yield (MSY) is a well-established concept that is mandated by legislation, and has a clear theoretical meaning in terms of a single stock. However, its definition is problematic in a multispecies setting, which makes it more difficult to apply the MSY principle. In this study of the North Sea fish community, we consider several...

Highlights o A Jacobian Matrix of all long-term yields on all current fishing mortality rates are shown for each available model. o These enable the principle interactions within and between species in each area to be compared. o These also allow the construction of a simple multispecies index for each species in each model in each area. o These al...

When making predictions about ecosystems, we often have available a number of different ecosystem models that attempt to represent their dynamics in a detailed mechanistic way. Each of these can be used as a simulator of large‐scale experiments and make projections about the fate of ecosystems under different scenarios to support the development of...

Fish population dynamics are affected by multiple ecosystem drivers, such as food-web interactions, exploitation, density-dependence and the wider environment. While tactical management is still dominated by single-species models that do not explicitly account for these drivers, more holistic ecosystem models are used in strategic management. One w...

When making predictions about ecosystems, we often have available a number of different ecosystem models that attempt to represent their dynamics in a detailed mechanistic way. Each of these can be used as simulators of large-scale experiments and make forecasts about the fate of ecosystems under different scenarios in order to support the developm...

The tools developed within the project help integrate natural science knowledge with social processes so as to aid decision-making in the three case study areas and at the European level. Properly formulated models will be a key part of the evidence base which will promote wise decision-making for the benefit of EU citizens and the wider world. Her...

Multispecies mixed fisheries catch ecologically interacting species with the same gears at the same time. We used an ensemble of size-based multispecies models to investigate the effects of different rates of fishing mortality (F) and fleet configurations on yield, biomass, risk of collapse and community structure. Maximum sustainable yield (MSY) a...

This poster shows how a multispecies and mixed fisheries model can be tuned to provide a simultaneous forecast of many fish stocks. These forecasts are then validated by means of a hindcast evaluation for the period 2010-2015. Results are presented which show that the model is potentially useful for making management decisions.

This "Action Plan" presents recommendations from the EcApRHA project (Applying an Ecosystem Approach to (sub) Regional Habitat Assessment) that can be used to progress OSPAR’s biodiversity monitoring and assessment towards the next Quality Status Report assessment and in its regional coordination role in support Contracting Parties’ implementation...

Complex computer models are used to predict how ecological systems respond to changing environmental conditions or management actions. Communicating these complex models to non-scientists is challenging, but necessary, because decision-makers and other end users need to understand, accept, and use the models and their predictions. Despite the impor...

The marine food web is considered to be a factor of key importance for the global carbon balance. The concept of the ‘Biological Pump’ refers to the mechanism by which CO2 fixed by photosynthesis is transferred to the deep ocean through biologically-driven processes, resulting in sequestration of carbon for a period of decades or longer. Stressors...

Demands for management advice on mixed and multispecies fisheries pose many challenges, further complicated by corresponding requests for advice on the environmental impacts of alternate management options. Here, we develop, and apply to North Sea fisheries, a method for collectively assessing the effects of, and interplay between, technical intera...

1.Implementation of an ecosystem approach to fisheries requires advice on trade-offs among fished species and between fisheries yields and biodiversity or food web properties. However, the lack of explicit representation, analysis and consideration of uncertainty in most multispecies models has limited their application in analyses that could suppo...

Parameter values in the unfiltered ensemble. Table S2. Diet matrix option 1 (Rochet et al. 2011). Table S3. Diet matrix option 3 with a cut-off diet fraction by numbers of 0·001 (Pinnegar & Platts, 2011). Table S4. Diet matrix option 4 with a cut-off diet fraction by numbers of 0·01 (Pinnegar & Platts, 2011). Table S5. Diet matrix option 5. Fig. S1...

The methodology of quantifying model parameter uncertainty to produce probabilistic forecasts and estimate confidence ranges for key outputs in the LeMans model is discussed. The process is outlined very briefly, some typical outputs are presented, and a couple of common questions concerning the use of outputs and the nature of the process are addr...

A variant of the operational forecast configuration of the Met Office’s newly developed Eulerian Air Quality Forecast Model was used to generate an air quality hindcast for 2006 as part of a DEFRA model intercomparison. Verification of predicted ozone concentrations was carried out by comparing against hourly observations from 15 rural and urban ba...

The on-line air quality model AQUM (Air Quality in the Unified Model) is a limited-area forecast configuration of the Met Office Unified Model which uses the UKCA (UK Chemistry and Aerosols) sub-model. AQUM has been developed with two aims: as an operational system to deliver regional air quality forecasts and as a modelling system to conduct air q...

The on-line air quality model AQUM (Air Quality in the Unified Model) is a limited-area forecast configuration of the Met Office Unified Model which uses the UKCA (UK Chemistry and Aerosols) sub-model. AQUM has been developed with two aims: as an operational system to deliver regional air quality forecasts and as a modelling system to enable air qu...

We apply a diagnostic based on moisture conservation in the atmosphere, integrated over planetary-scale ocean basins and drainage areas to evaluate freshwater fluxes over the ocean surface to three generations of the Hadley Centre climate model (HadCM3, HadGEM1 and HadGEM2-AO). The coherent inclusion of runoff by the diagnostic enables model surfac...

The radiative forcing due to a distinct pattern of persistent contrails that form into contrail-induced cirrus near and over the UK is investigated in detail for a single case study during March 2009. The development of the contrail-induced cirrus is tracked using a number of high-resolution polar orbiting and lower-resolution geostationary satelli...

Volcanic ‘super-eruptions’ have been suggested to have significantly influenced the Earth’s climate, perhaps causing glaciations and impacting on the human population. Climatic changes following a hypothetical ‘super-eruption’ are simulated using a coupled atmosphere ocean general circulation model, incorporating scaled volcanic stratospheric aeros...

The thermohaline circulation (THC) is an important component of the climate system which transports large amounts of heat northwards in the Atlantic sector. It is still unclear why there is no counterpart in the Pacific, and whether this absence is coincidental or fundamental. We investigated the relative importance of various geographical asymmetr...

FAMOUS is an unfluxadjusted coupled atmosphere-ocean general circulation model (AOGCM) based on the Met Office Hadley Centre AOGCM HadCM3. Its parametrisations of physical and dynamical processes are almost identical to those of HadCM3, but by virtue of reduced horizontal and vertical resolution and increased timestep it runs about ten times faster...

As part of the Coupled Model Intercomparison Project, integrations with a common design have been undertaken with eleven different climate models to compare the response of the Atlantic thermohaline circulation (THC) to time-dependent climate change caused by increasing atmospheric CO2 concentration. Over 140 years, during which the CO2 concentrati...

We have undertaken a comparative study of the mechanisms which drive the response of the Atlantic thermohaline circulation (THC) to a fourfold increase in CO2 over 70years with stabilisation thereafter in HadCM2 and HadCM3. In both models, the THC changes are driven by surface flux forcing, with advection (and diffusion in HadCM2) acting in the opp...

The Hadley Centre climate model HadCM3 simulates a stable thermohaline circulation driven by deep water formation in the Norwegian and Labrador Seas without the need for flux adjustments. It has however been suggested that this result is the fortuitous consequence of the local use of the Roussenov convection scheme in this region, and that the mode...

We describe a new method for evaluating the radiative forcing, the climate feedback parameter (W m-2 K-1) and hence the effective climate sensitivity from any GCM experiment in which the climate is responding to a constant forcing. The method is simply to regress the top of atmosphere radiative flux against the global average surface air temperatur...

Initial results are presented from a 150-yr control and an 80-yr transient simulation of a new global coupled climate model with an ocean model resolution of °, which is sufficient to permit ocean eddies to form. With no spinup procedure or flux correction, the coupled model remains close to radiative equilibrium, and the enhanced ocean resolution...

The Atlantic thermohaline circulation (THC) plays an important role in global climate. Theoretical and palaeoclimatic evidence points to the possibility of rapid changes in the strength of the THC, including a possible quasi-permanent shutdown. The climatic impacts of such a shutdown would be severe, including a cooling throughout the Northern Hemi...

A fast GCM has been developed. FAMOUS (FAst Met Office / UK Universities Simulator) is a general circulation model based on HadCM3 but which runs 10 times faster due to reduced resolution and increased timestep. It does not require the use of flux adjustments. Such a model is an invaluable tool for very long timescale integrations and for large mul...

Models of the North Atlantic thermohaline circulation (THC) show a range of responses to the high-latitude warming and freshening characteristics of global warming scenarios. Most simulate a weakening of the THC. with some suggesting possible interruption of the circulation, but others exhibit little change. The mechanisms of the THC response to cl...

 The possible future impact of anthropogenic forcing upon the circulation of the Mediterranean, and the exchange through the Strait of Gibraltar is investigated using a Cox-type model of the Mediterranean at 0.25° × 0.25° resolution, forced by “control” and “greenhouse” scenarios provided by the HadCM2 coupled climate model. The current structure o...

This paper is part of the special publication Gas hydrates: relevance to world margin stability and climatic change (eds J.P. Henriet and J. Mienert). The rapid climate changes at the terminations marking the end of the last glaciation are poorly understood. CH 4 hydrate decompositiion has been suggested as a possible trigger of deglaciation. This...

The rapid climate changes at the terminations marking the end of the last glaciation are poorly understood. This study uses the Cambridge two-dimensional atmospheric model to investigate the impact of a large marine sediment slump or permafrost rupture releasing 4000 Tg of CH4 into the high latitudes of the northern hemisphere, with particular emph...

Current research into equilibrium climate sensitivity focuses on atmospheric and land surface feedback mechanisms while ocean processes are thought to influence the transient climate response. Ocean circulation changes however, can also act as an important feedback mechanisms by affecting changes in the pattern of heat distribution around the clima...