Towards an understanding of conservation impact

Simon Black – 

Monitoring and evaluation is a common headache for conservation leaders. how do they evaluate the impact of a programme, intervention, or project? One of the big problems is that conservation professionals cannot attribute ’cause and effect’ to their interventions, so assume that they cannot suggest or claim that improvements have been ’caused’ by their intervention.

This false modesty is a problem, because it encourage even more spurious claims in its place – like recovery of species on a global scale, or a discussion of increased population counts when other factors may be involved. Few can claim (although some can truly claim with certainty)  that without intervention an extinction would have occurred.

We end up in a spiral of despair – will anything we do make a difference?

A new approach to leadership is required. This includes seeking ways of understanding the impact of conservation work on the systems of concern. this means understanding the status of the species and ecosystems involved. That understanding will never be complete – there will be many gaps and unknowns.

For example, the status of a species will not be known merely from its population size. There are many demographic, genetic, health and range-related factors well as an understanding of threats. However often there is no such data available nor the resources to measure and monitor these factors. In some instances we might not even know the baseline or historic situation for the species or ecosystem.

To improve our understanding  in these situations the first thing that needs to be done is to start looking at the available data over time. Instead of a snapshot look at the dynamics of the data as a surrogate measure of the status of the species.

In this cas

In this case a population of birds remains stable (Pungaliya et al 2018)

e a bird population has declined in size, but has become more stable  and less prone to fluctuations in size (Pungaliya and Black 2017).


If we look at a threat, such as deaths of manatees in human-built lock and canal systems, we can start to see if the situation is improving, or not. In this case, new control systems on lock has reduced the number of deaths (Black and Leslie 2018)

Statistically derived limits (defined by the data itself and NOT an ‘expert view’) enable us to see whether actual changes can (i) be identified and (ii) be attributed to any actions taken in terms of conservation effort.

We can start to consider management conservation for real improvements.

Further reading:

Black SA and Leslie SC (2018) Understanding impacts of mitigation in waterway control systems on manatee deaths in Florida. Int J Avian & Wildlife Biol 3 (5), 386‒390.

Pungaliya AV, Leslie SC, Black SA. (2018) Why stable populations of conserved bird species may still be considered vulnerable: the nihoa finch (telespiza ultima) as a case study. Int J Avian & Wildlife Biol. 2018;3(1):41‒43.

Pungaliya AV, Black SA. (2017) Insights into the recovery if the palila (Loxioides bailleui) on hawaii through use of systems behavior charts. Int J Avian & Wildlife Biol. 2017;2(1):4‒5.

Developing more impactful conservation

Simon Black – 

Does conservation have the capacity to learn new ways of designing, testing and improving its interventions and impact? Good disciplines of management can be learned from other sectors, but still need to be applied, whether in the field, in zoos, and in collaborations with scientific institutions, governments and communities. The conservation sector is blessed with a motivated workforce – people who are committed to the recovery and survival of species and ecosystems and we need to make better use of their motivations.

Impact will not be amplified just through our best efforts which, whilst worthy, will essentially involve pushing water uphill (Deming, 1994). Rather we need to ‘work smarter’ by finding a better way to protect, recover and restore. This is not a far-fetched expectation, shown by examples of dramatic turnarounds with species like the Mauritius Kestrel and Echo Parakeet. It is a question of learning.

Conservation needs to apply new methods of problem identification, decision making, planning, monitoring and review, even in situations where we already have a sound understanding of conservation science of the species? I am always surprised by the frequency of projects that, despite available expertise and resource, are hampered either by people rigidly sticking to outdated plans of action, or by being allowed to drift off course due to the pursuit of ill-conceived goals. These are symptoms of a hesitant or uninformed management approach. Science cannot provide the answers to these problems (Clark and Reading, 1994).

Conservation practitioners also need to learn how to grapple with scientific uncertainty, building arguments for the recovery of species in situations of scant information. Decisions of critical importance (such as how to save the last few individuals) can rely on little more than hunches, best guesses or deep assumptions; an approach which flies in the face of scientific expectations for decision-making based on hard evidence (Game et al., 2013). A vast proportion of thorny conservation problems are rooted in issues around people (either the ones generating the threat or the ones implementing the action) rather than biology. In the face of these demands only now are we beginning to realise that the old ways of managing conservation can be radically improved through skills which enhance thought, courage and emotional insight alongside better collaboration and creativity (Black and Copsey, 2014).

Aside from practitioners needing to acquire management skills, there is a second side to this; the humility to lead effectively. A conservation professional that is prepared to admit “I don’t know” is ready to pursue the right knowledge. The project manager who is prepared to admit “it is not working” will be ready to experiment with new solutions. The leader who is prepared to ask “what can we learn?” when someone has made a mistake will enable even the most experienced team to gain new insights into their work. This is a new horizon for many conservation professionals and it is not on the curriculum of a biological sciences degree. How much are we, as conservation managers, prepared to change the way we think?

Fortunately we can call on nearly 100 years of sound management theory and practice, tested and validated through scientific study of psychology, statistics, experimental design, human behaviour and organisational theory. Good conservation management practice; working with species, people, resources, logistics, problems and policies requires a both a disciplined and passionate approach – an appreciation of the importance of long-term vision of what we need to achieve, alongside an understanding of the practical realities required to set meaningful short-term goals (Black, Groombridge & Jones, 2013).

Many aspects of this ‘better way’ of managing (Deming 1994) are reflected the basics of effective conservation; knowing the species (morphology, behaviour, ecology nutrition, reproduction and its natural history) and understanding the threats, followed by a pursuit of ever-improving knowledge (husbandry, enclosure requirements, health management), usually alongside practical interventions (intensive management, captive breeding, community engagement). Often the tangible gains in recovering species are made through incremental improvements in knowledge and these changes start with anecdotal evidence of what works and what doesn’t. Over time, with good data management and systematic project design (data monitoring, planning and method development) the accumulation of anecdotes becomes data of scientific value. Scientific understanding thereafter enables wider questions to be explored and better understanding of species, communities and whole ecosystem recovery. There are many examples where a blossoming of scientific knowledge has run in parallel with concrete progress on the ground (Young et al., 2014).

It is an exciting time to be a conservation professional and an important time for zoos and field projects to adapt, learn and accelerate improvement: a better way for conserving species and ecosystems.


Black S.A. (2014) Can we engineer an exponential growth in conservation impact? Solitaire 25: 3-5. Durrell Conservation Academy, Jersey.  ISSN 2053-1087.

Black S.A. and Copsey, J.A. (2014) Purpose, Process, Knowledge, and Dignity in Interdisciplinary Projects. Conservation Biology, 28 (5): 1139-1141.

Black, S. A., Groombridge, J. J. and Jones C. G. (2013) Using better management thinking to improve conservation effectiveness. ISRN Biodiversity

Clark, T.W., Reading R.P. (1994) A professional perspective: improving problem solving, communication and effectiveness. p351–369 in T.W. Clark, R.P. Reading, A.L Clarke, eds. Endangered species recovery: finding the lessons, improving the process. Island Press, Washington, D.C.

Deming,W. E. 1994. The new economics for industry, government, education. 2nd edition. Massachusetts Institute of Technology, Center for Advanced Engineering Study, Cambridge.

Game, E.T., Meijaard, E., Sheil, D., McDonald-Madden, E. (2013). Conservation in a wicked complex world; challenges and solutions. Conservation Letters 7 (3): 271-277

Young, R.P., Hudson, M.A., Terry, A.M.R., Jones, C.G., Lewis, R.E., Tatayah, V., Zuel, N., Butchart, S.H.M. (2014) Accounting for conservation: Using the IUCN Red List Index to evaluate the impact of a conservation organization. Biological Conservation 180:84-96





Unpacking the processes of effective conservation effort: Demand-Value-Flow

Simon Black – 

The identification, definition and management of key processes is an important element in understanding the value of the conservation interventions. however, most conservation leaders rarely even identify their core processes, let alone manage them for improvement. This shortfall has been repeatedly observed in organisational research in conservation (Black and Copsey 2014; Black, Meredith et al, 2011; Moore et al, 2018). It is more usual for work to be defined in strategic plans (often detailing activities to the fine details) and managed through work plans (including schedules and milestones). Success is often erroneously debated in terms of ‘activities completed’, objectives achieved’, ‘outputs’, or ‘outcomes’ and reported as such in formal reports and scientific papers alike, in the hope this provides some form of management wisdom. It barely provides a partial picture. Unfortunately these measures rarely reflect the fundamental nature of conservation, namely that it involves on-going and continuing efforts and outcomes.

On-going activities need an understanding a knowledge of process.

In process terms there is no difference between an ‘output’ and an ‘outcome’ – they just relate to sub processes and large (or further extended) processes. The boundary of the process defines the level of measurement. A poorly defined boundary could derive an effective, but futile process which pumps out good results but has no sustainable effect on its ecosystem of concern, such as a captive release programme which puts animals into a degraded habitat where animals only succumb to extant threats. Graham Caughley saw this as a major weakness in conservation in the 1990s, but the lessons are still not fully understood.

The lack of process definition was a classic problem observed in the early years of the Black Footed ferret rescue programme (Black and Groombridge, 2011). A productive captive breeding programme was undone by releases which saw most animals die in a short time in the wild. To remedy this a wider process of reintroduction needed to be defined, which incorporated pre-release conditioning of the animals (e.g. aversion to humans and domestic animals), vaccination of ferret kits, vaccination of prey in the wild locations, as well as careful selection of release locations themselves. only when the total process was defined and measured for improvement did reintroductions start to succeed and predictably achieve the right results.

Flow is another key concept in process management – getting things in the right order. The Po’ouli succumbed to extinction as milestones for achievement were followed which did not meet the perilous status of the bird in the wild. Whilst huge (and commendable) effort was made to construct fenced habitat, free from invasive species, sadly the bird population itself fell into decline. There was no knowledge or effort or success  in even considering breeding the birds, neglected until only three aged individuals remained (Black and Groombridge, 2011).

Of course, to measure process performance (as opposed to project outcomes) you need an understanding of performance over time. this requires new measures and analyses of longitudinal data – Systems Behaviour. Only understand variation in process performance can give the helpful feedback insights needed to accelerate improvement in a timely and meaningful manner (Seddon 2003; Black et al, 2013). Anything other would be ‘trial and error’.

Finally a conservation manager must define a process by the needs of the species and ecosystems of concern. Form a practical point of view this is likely to be driven by an understanding of threats – the ‘demands’ placed on the species. the process should then deliver something of value that addresses those threats. Anything less than value is just us, as humans, keeping ourselves busy. Being busy might make us feel better, but it is unlikely to ever help to conserve species and ecosystems.


Black S. A. and Groombridge J.J. (2010) Use of a Business Excellence Model to Improve Conservation programs, Conservation Biology, 24 (6): 1448–1458.  DOI: 10.1111/j.1523-1739.2010.01562

Black, S. A., Groombridge, J. J., & Jones, C. G. (2011). Leadership and conservation effectiveness: finding a better way to lead. Conservation Letters, 4(5), 329-339.

Black S. A., Meredith, H.M.R. and Groombridge J.J. (2011) Biodiversity Conservation: applying new criteria to assess excellence, TQM and Business Excellence 22 (11): 1165-1178

Black, S. A., Groombridge, J. J., & Jones, C. G. (2013). Using better management thinking to improve conservation effectiveness. ISRN Biodiversity, 2013.

Black, S. A., & Copsey, J. A. (2014). Purpose, process, knowledge, and dignity in interdisciplinary projects. Conservation Biology, 28(5), 1139-1141.

Black S.A. (2015) System behaviour charts inform an understanding of biodiversity recovery. International Journal of Ecology, 2015 (787925): pp6

Caughley, G. (1994) Directions in conservation biology. J Anim Ecol 63, 215–244.

Moore A.A., Weckauf, R., Accouche, W.F. and Black, S.A. (2018) The value of consensus in rapid organisation assessment: wildlife programmes and the Conservation Excellence Model. Total Quality Management & Business Excellence

Seddon, J. (2003) Freedom from command and control. Vanguard Press, Buckingham, UK.


Let’s not have species and ecosystems paying for the mistakes of conservation organisations

Simon Black –

I am optimistic for the future of conservation and for the impact that dedicated professionals and committed communities can make for species, ecosystems and landscapes. Time and again I encounter individuals and teams who are doing fantastic work devising interventions which make a difference.

But we must remember, as leaders, that the best efforts of people are not enough, and may sometimes even be damaging. Instead it is our use of KNOWLEDGE and applying it to understanding what to change to enable improvement that really counts. This is not ‘knowledge for knowledge sake’ – it is not ‘research for our interest only’.

It is about being purposeful. Knowing what we want to achieve, understanding the method to achieve it (including how to test out the method) and knowing, through measurement, when we have accomplished our purpose (or at least if we are on the way to accomplishing it).

Thankfully there are professionals who are now exploring new ways of implementing initiatives, of working with key communities, of understanding how to accelerate the recovery of ecosystems. This is not easy work and often requires convincing others of new ways of operating – throwing off the suffocating security blankets of conservation goals, plans, strategies and techniques. But this is necessary, in order to cut through the blinkered thinking and bureaucracies which hamper progress or prevent innovative thinking.

Species and ecosystems eventually pay for the delays and mistakes of conservation, just as, in the observation of Deming, consumers and society pay for the mistakes and delays of industry through a reduced standard of living.

If we as conservation professionals rely on complex investment, planning, prioritisation, science, training and human resource strategies without focusing on the real issues that impact on improvement of ecosystems, then we risk wasting money, opportunity, influence and reputation. In the long term it will be species and ecosystems which pay.

Let us, as conservation leaders, take a better path to achieving conservation of the vital biodiversity that shares the planet with us.


Black SA, Copsey JA (2014). Purpose, Process, Knowledge and
Dignity in Interdisciplinary Projects. Conserv Biol 28(5): 1139-1141.

Black SA, Copsey J (2014) Does Deming’s System of Profound
Knowledge Apply to Leaders of Biodiversity Conservation? Open
Journal of Leadership 3: 53-65.

Coonan TJ, Schwemm,CA, & Garcelon DK (2010) Decline and recovery of the island fox: a case study for population recovery. Cambridge University Press.

Leslie SC, Blackett FC, Stalio M, Black SA (2017) Systems Behaviour Charts for Longitudinal Data Inform Marine Conservation Management. J Aquac Mar Biol 6(5): 00171. DOI: 10.15406/jamb.2017.06.00171

Martin, T. G., Nally, S., Burbidge, A. A., Arnall, S., Garnett, S. T., Hayward, M. W., … & Possingham, H. P. (2012). Acting fast helps avoid extinction. Conservation Letters, 5(4), 274-280.

Pungaliya AV, Black SA (2017) Insights into the Recovery of the Palila
(Loxioides bailleui) on Hawaii through Use of Systems Behaviour
Charts. International Journal of Avian & Wildlife Biology 2(1): 00007.

New paradigms needed for managing conservation change

Simon Black –

Traditional conservation practice follows a couple of familiar paradigms.

The first involves an enthusiast taking up a cause, for a particular species or landscape. that enthusiasm maybe a scientific professional, a lay person with a personal interest , or a local community member. Progress is reliant on the wit and wisdom of that individual and their ability to gather together the necessary resources and support to make things happen. Progress may take weeks, month, years, decades. I have seen this with individual scientists following lone paths in places like Hong Kong, Assam, Madagascar, Comores, Oman, and the Cayman Islands. It is a path well trodden by well-known individuals like Dian Fossey, Gerald Durrell, Tom Cade, and Peter Scott. it is admirable and without exception reliant on determination and a long term view.

A second paradigm is where better-organisaed and resources NGOs or government departments take up the mantle of work using their own infrastructure and methods. This is a ‘conservation plus’ approach which takes the form of time bound period of work (driven by funding cycles) which is generally called ‘a project’, or if a series of funding cycles can be strung together into a coherent, long-term approach ‘a programme’. this is the most common form of conservation work. The excellent work with the California Channel Island fox is a good example.

A third form of approach has emerged as NGOs and governments have realised the need for long term interventions, most easily observed in USA ESA  species such as the California Condor or black-Footed Ferret, but also in successful programmes on the coastal and oceanic islands of New Zealand and programmes on mainland Australia.

As larger-scale landscape approaches are recognised as important, the long-term model has been broadened to supply a funding infrastructure or socio-economic system that enables long term recover and incentives to establish new landscape and species protection. These large-scale approaches are observed in the Atlantic forest states of Brazil with water catchment and reforestation initiatives involving private landowners and land users across a mosaic landscape.

These types of systemic approach which establish human use of natural landscapes within certain ‘acceptable’ parameters (e.g. sustainability or biodiversity recovery) offer a dramatic shift in how we as humans can re-engage with the natural world.

However it is not enough. Emergency action is still required – recovering populations, preventing poaching, breaking illegal trade, halting forest destruction. These all require major change and interventions which will make a dramatic difference.

Unfortunately the traditional project management mindset will never deliver the required speed of change. Project management is the poorest method for delivering change (especially change that requires a shift in psychology of key stakeholders). Project management is alos applicable where a known design and outcome is specified – yet in conservation the complexity of ecosystems, socio-economic systems and species behaviour is rarely predictable.

A different approach is required – and conservation managers need to be ready to take it on.

Matching capability with purpose

Simon Black –

Any team needs to deliver the work that achieves its purpose. Getting people up to the right level of ability is important. This capability covers skills, awareness of the work, clarity on the goals and a sense of purpose that enables (i) prioritisation of effort, (ii) decision making and (iii) problem solving.


A recent study in Mauritius by Stebbings et al (2016) identified that operational teams made up of significant numbers of new starters (e.g. seasonal volunteers or incoming professionals) found that those new colleagues only achieved the desired level of performance part-way through the peak breeding seasons for working with endangered birds.

The arrangement for taking on new staff was historical and fitted a plan of when people would be at their busiest. However this study showed that taking people on earlier and training them to a higher level would make them more productive at the busiest times.


Stebbings, E. , Copsey, J. , Tatayah, V. , Black, S. , Zuël, N. and Ferriere, C. (2016) Applying Systems Thinking and Logic Models to Evaluate Effectiveness in Wildlife Conservation. Open Journal of Leadership, 5, 70-83. doi:10.4236/ojl.2016.53007.

Starting with little, to achieve something great

In conservation we are working in the business of change. We want to improve the situation for a species, or remove threats, or recover a landscape, or enable humans to co-exist  with a sustainable natural environment.

As humans within human society and as biologists working with species and ecosystems we need to recognise that change is not a cause-effect process. Instead we should think of it as an emergent property – an outcome of many interventions and interactions with the things we are concerned about and their wider environment.

It is almost inconceivable that a rhino has recently been killed in a French zoo by poachers for its horn . Yet this is an outcome from changes in the system – the the need for income by criminals, the demand for horn, the depletion in accessibility to alternative wild supplies (due to better wildlife protection). We need to truly understand the dynamics in order to eliminate the threat and this takes constant learning – what worked before might not be relevant today. This sometimes seems too much to tackle.

We cannot do everything today. So how do we start?

Black Robin. Photo originally by schmechf, modified by Wikimedia Commons.The best processes of learning, improvement and innovation start small and grow big. This is also true in many cases within the conservation sector.

The Chatham Island Black Robin, Mauritius Kestrel and other species have been brought back from the brink by making initial steps, learning and continuing to make those steps. Start small and then build up. This strategy enables us to move fast and act, but most importantly learn, improve and upscale carefully. These examples are clearly not as complex or global as the system that impacts rhino conservation, but we must never be too afraid to learn how to innovate.


Further reading:

Gagliardo, R., Griffith, E., Mendelson, J., Ross, H., and Zippel, K. (2008). “The principles of rapid response for amphibian conservation, using the programmes in Panama as an example”. International Zoo Yearbook 42 (1): 125–135.

Herrero, L. (2006) Viral Change, meetingminds, UK.

Martin, T. G., Nally, S., Burbridge, A. A., et al. (2012). Acting fast helps avoid extinction. Conservation Letters, 5, 274-280.


Relevant links:


The only plan is to gain knowledge

Simon Black –

Traditional change management follows a linear approach, defining a goal, identifying a plan and delivering to that plan. The process is logical and surely unquestionable. However this is an example of linear thinking, which is rarely the appropriate way to consider complex conservation problems.

Ecosystems, landscapes, habitats, communities, species, populations do not act in a linear fashion, they are much more complex. This means that if you change one thing then something unexpected is likely to happen somewhere else – and what you had intended may or may not happen.

Of course understanding systems can be a difficult thing to do. Instead, managers either resort to ‘giving their view’ on things, or setting success measures based on those views. Having a view on why things are a problem is one thing, but  it is better to get knowledge by collecting data (Deming 1993; Seddon 2005).

It is better to define the following:

  • Purpose is the definition of why we are here, best understood from the species or ecosystem perspective.
  • Measures allow us to understand what is likely to happen in future if the system (including human community interactions, commercial industrial or agricultural land use, wildlife trade etc) doesn’t change.
  • Method – can be addressed when we understand the data derived from our measures.
Manatee deaths due to watercraft collisions in Florida. Knowing the occurrence level (Measure) can we do anything (Method) to reduce unnecessary mortality of manatees (Purpose)?

Systems Theory tells us that Purpose, Measures and Method are fundamentally linked – it is a systemic relationship. This systemic relationship can either work for you or against you depending on how you set things up.

The paradox is that in this system, change requires no plan. For Seddon, change is simply an emergent property. It can only occur if you set things up that enable people to innovate with interventions in response to the real system of species and ecosystems – what happens.

Any attempt to plan change otherwise is fiction.



Deming, W.E. (1993) The New Economics, MIT CAES, Cambridge MA.

Seddon, J. (2005). Freedom from Command and Control. Buckingham: Vanguard Press.



Insights taken from an Understanding of Variation: (iii) Real improvement can be isolated from random noise

One of the most important things for conservation practitioners to be able to do is to detect real improvement (or real declines) from otherwise random changes for a species or ecosystem (Black and Copsey 2013).

Systems behaviour charts allow you to identify the difference between random changes and non-random changes -to see whether the ‘system’ has fundamentally changed if we use the rules summarised by Black (2015)

If we take the example of the recovery of Puerto Rican Parrots, initially managed by Snyder et al (1987) in the 1970s and 1980s, we see phases of the parrot population going up and down over time, some points above a mean line and some below (as you would expect).puerto-rican-parrots-chart

Where the pattern of data falls outside this expectation, the system has fundamentally changed. In the case of the Puerto Rican parrots, this occurred in 1978 and again more fundamentally in  1989. It even looks like a new breakthrough may follow on from 2009.

Even more important than the actual numbers however, is the insight from plotting natural limits and warning limits. For the parrots we see that although the population is generally improved it is not stable and could be expected throughout the 2000s to drop to less than 10 birds as much as rise to 65. Indeed today’s population could yet be vulnerable to extinction – with a projected lower natural limit appearing to be below zero using most recent year’s data .


Black S.A. (2015) System behaviour charts inform an understanding of biodiversity recovery. International Journal of Ecology, 2015 (787925): pp6

Black S.A. and Copsey J.A. (2014) Does Deming’s ‘System of Profound Knowledge’ Apply to Leaders of Biodiversity Conservation? Open Journal of Leadership  3(2) 53-65. DOI: 10.4236/ojl.2014.32006

Snyder,N. F. R. , Wiley, J. W. and Kepler, C. B. (1987) The Parrots of Luquillo: Natural History and Conservation of the Puerto Rican Parrot,Western Foundation of Vertebrate Zoology, Los Angeles, Calif, USA.

110 Success Stories for Endangered Species Day 2012: Puerto Rican parrot (Amazona vittata), March 2015,

Endangered Species Act Works: Puerto Rican parrot Amazona vittata, 2015, works/caribbean.html.

Insights taken from an Understanding of Variation: (ii) A moment in time…is never enough to understand the whole story

manatee-mortality-figureThe status of any situation cannot be best judged from an isolated point in time. It is also dangerous to judge one point in time versus another point in time (such as this year versus last year). Consider this in the case of a population of rare birds, or the status of your budget, or the number of volunteers in your organisation. The only meaningful understanding of a data point is where it sits in the context of the past, and ideally, the future. For example if we look at manatee boat-collision mortality (right) and we have an annual count of 50 manatee deaths, is that good., bad or indifferent?

Prediction of the future is one of the most important but elusive skills that a manager can possess. Of course no one can actually predict the future, but we can identify predictable elements, or degrees of predictability. The best methods for prediction are based on using empirical data. In management circles, rather than establishing complex predictive models, the most pragmatic approach is to establish a picture of the current system and then base expectations on the predictability of the patterns of data in that system. For example with the Florida Manatee (above) we see three (or four) systems  – a stable low level of collision deaths (to 1983), then a higher level from 1984-1997, then an unstable period 1997-1999, then a new system thereafter. You have to loo at the right system to understand what might happen next.

It is also unhelpful to define a level of performance as ‘good’ or ‘bad’. They key thing is how to stabilise it and how to make it better. The system in the 1990s is driven by the higher numbers of watercraft on the river systems – so collisions are more likely. We cannot say things are worse than in the 1970s, just that the likelihood of collision deaths is greater – and we might want to do something about that (such as impose slower waterway speed limits).


Black S.A. (2015) System behaviour charts inform an understanding of biodiversity recovery. International Journal of Ecology, 2015 (787925): pp6