What are we aiming for in conservation? Systems of biodiversity protection

If all required funding and resources became available, what would the ultimate aim of conservation work be? Conservation organisations are invariably limited by resources (e.g. available land), funding and, crucially, time and so in reality conservation efforts aim to make the most of what is available in order to achieve the highest conservation impact possible. The possibility of completely achieving this mystery aim of conservation seems so remote that it is rarely discussed in these terms. There is some discussion over what exactly to conserve, e.g. particular species (such as keystone species), biodiversity, genetic diversity, viable populations or ecosystems, but are there other intrinsic values in nature to be conserved? It is worth investigating this topic in order to better understand why we aim to conserve at all and to be open to exploring alternatives to traditional conservation approaches. Conservation efforts attempt to achieve various explicit final aims at present, ranging along a continuum of varying human involvement. The value and ethical considerations associated with these aims as conservation goals will be discussed and alternative approaches explored.

Why conserve?

There are many motivations for conserving biodiversity, from human-orientated reasons such as maintaining ecosystem services (e.g. crop pollination) and preserving potential medical resources to conserving biodiversity for the conservation of more biodiversity (i.e. an ecosystem may be more resilient to change if it is more diverse) and conservation due to the intrinsic value of a species. Intrinsic value can be difficult to articulate though many implicitly understand this value; this topic is discussed in a previous post. In this post it is accepted that biodiversity has a high intrinsic value, rather than only direct or indirect value to humans.

What to conserve?

Exactly what conservation aims to enable to survive is a debated topic. Even if overall biodiversity is accepted as the main aim, this may be conducted through focussing on biodiversity hotspots, work to protect specific at-risk species or using a triage system, where only species/areas/ecosystems which are thought to be likely to survive with intervention are protected while those with outcomes unlikely to be greatly improved by intervention are left with a lower level of protection. However, overall biodiversity can be a difficult concept to define – how is genetic or taxonomic diversity considered? In addition to this, conservation of entire ecosystems may be neglected by focussing only on diversity – while maintaining ecosystem health may be a good way to conserve biodiversity, this means that the conservation of a diversity of ecosystems for their intrinsic value may be at risk. Here, different systems used in conservation efforts and their ethical implications will be discussed.

Existing conservation aims and their ethical implications

Ranging from the lowest to highest level of human intervention in the system conserved, conservation efforts include preservation of “pure” wilderness, re-creation of ecosystems of the past since destroyed, human-managed semi-natural/quasi-natural ecosystems, artificial managed ecosystems and artificially maintaining biodiversity in captivity.

 

Pure wilderness

Attempts are made to preserve existing areas of wilderness in their original state, with little human interaction or intervention other than to maintain the level of protection from harm or development. Species interactions are allowed to continue as they would without human presence, requiring a large area to be protected to minimise edge effects where bordering human managed land. 

There are many reasons why this is a worthwhile aim in conservation, ethical and otherwise. These areas of wilderness are valuable as a reference for scientific research and to better understand how to approach other conservation efforts. Wilderness can also be considered to have an intrinsic value beyond that of the biodiversity it supports; Singer points out that areas such as this have a value to humans as a link to the past, similar to the value of an ancient monument [2]. In this way, wilderness areas have an incalculable value as this link cannot be recreated once an area of wilderness has been destroyed or modified.

Does the status of wilderness areas as “natural” contribute to their intrinsic value? Would a human created and managed reserve, otherwise identical to a wilderness area, have a lower intrinsic value? The evolutionary and ecological processes involved in shaping these wilderness areas cannot be replicated, and so they have a type of scarcity value but perhaps also should be given a value based on the fact that they existed on the planet before humans and so should be allowed to continue to do so, provided they are not harmful to human well-being. In this way, the “natural” status of a wilderness area contributes to its value, adding to the sum of the intrinsic values of the individual species which are sustained by it.

Moving beyond biodiversity conservation, protecting wilderness areas also involves protecting the non-living landscape, such as rivers and mountains. These aspects of a wilderness area add further value based on the argument above, as they too were formed by the pre-existing processes of the planet. A mountain destroyed to make way for a human endeavour and rebuilt elsewhere would have lost a great deal of its value, according to this argument.

However, there are reasons to be cautious about using a pure wilderness model for conservation. Ecological constraints mean that only very large areas can be useful as unmanaged/lightly managed wilderness, as the effects of interacting with bordering non-wilderness areas will need to be minimised and populations will need to be of a viable size to survive without being connected to other sites or protected by additional management (e.g. predator control, managing their food sources).  Wilderness sites tend to be located in areas where there is limited scope for other uses by humans, e.g. mountainous areas [1], and so may not protect a representative selection of species and ecosystems; some systems may already be entirely lost in their “pure” state. It would be risky to rely solely on wilderness areas for biodiversity conservation for this reason as well as lowered resilience to change due to a potential lack of connectivity between sites if the only states which exist are wilderness and entirely developed areas, with nothing in between.

The concept of conservation of pure wilderness presents issues regarding the place of humans in nature. Wilderness areas protected for the conservation of biodiversity usually incorporate a very low level of human involvement. Human involvement is often seen as “unnatural” (see parts of this post on nature and morality) but we evolved on this planet as other species did. So humans can be classified as either unnatural, where nothing we do can be considered natural, no matter how similar to other acts of behaviours seen in nature, or as natural, where everything we do is a result of a natural process, no matter how industrial or technological and seemingly unlike nature, because we evolved the ability to do these things. Attempting to assign some human acts as natural (e.g. eating vegetables) and others as unnatural (e.g. moving around the world quickly in aeroplanes) often means that arguments are based on arbitrary lines being drawn between natural and unnatural acts, but classifying humans as entirely natural or unnatural causes complications for wilderness conservation – what is the place of humans in such a system? Should we be entirely uninvolved in order to maintain the wilderness status of an area or is there a role for us here?

 

Rebuilding ecosystems

Attempts may be made to reconstruct ecosystems which existed in the past but have since been modified or destroyed through human actions. This may take the form of habitat creation or a species reintroduction in which humans have a mainly supervisory monitoring role to ensure the new system is functioning well, after the more intensely managed initial stages while the system is being set up or investigated for its viability. 

This system comes a close second to pure wilderness, as it still maintains the intrinsic values of the species as well as partially upholding the value of a “natural” system in which ecological and evolutionary processes can carry on as, in theory, once the ecosystem is set up it will function according to ecological principles. However, the link with the past has been broken, but once this has occurred then recreating an ecosystem may be the next most ethically ideal option. If these functioning ecosystems are considered to have high intrinsic value, then there may be an element of justice involved in humans working to right the wrong our species committed through allowing or causing the ecosystem damage in the past.

Another ethical issue involved in rebuilding ecosystems, especially when this involves a species reintroduction, is conflict with modern human interests. Although humans and the ecosystem in question coexisted in the past, they may not have done so in recent times, such as wolves in the UK. This issue tends to focus on species reintroductions as an inconvenience to human activities. This may or may not be a moral issue, depending on whether concerns of humans living where a reintroduced species may spread to are trivial or worth genuine consideration in establishing the ethical case for a reintroduction. For example, if a reintroduced species is likely to cause harm to human wellbeing then this is an ethical issue as sentient beings may suffer in some way. If the human issue with a reintroduction is concerned with aesthetics or based on unfounded prejudice, then this is less likely to be considered as a moral issue unless great distress will be caused.

 

Human-managed nature reserves

Many modern, conventional nature reserves consist of semi-natural ecosystems which are maintained through a moderate level of management by humans, such as regularly removing invasive species or planting suitable food plants. This approach seems to be a workable balance, contributing towards biodiversity conservation with an achievable and realistic aim.

Similar to species reintroductions, the moral value of managed nature reserves comes from the intrinsic values of species protected and partially from providing the opportunity for ecological and evolutionary processes to continue. The full intrinsic value of ecosystem processes is not protected by this type of conservation as human input is used to modify and support the ecosystem, though the level of human input varies greatly between reserves. Potentially contrasting with the reintroduction scenario, these ecosystems may be lacking some species now locally extinct, which alters the intrinsic value of the ecosystem as the link with the past has been lost. Despite these modifications and apparent reductions in moral value, this type of conservation is extremely valuable in the practical conservation of threatened species; it is an effective, real-life solution, protecting the straightforward intrinsic value of the species on the reserves, improving biodiversity (with its intrinsic value) through increased connectivity across a landscape and partially maintaining ecosystem processes - meaning that this is a worthwhile conservation aim.

 

Biodiversity-friendly artificial ecosystems

Next along the scale from managed nature reserves are ecosystems which exist only because humans have created them, such as farmland and gardens, which are the subject of efforts to make them suitable and useful for maintaining biodiversity. Examples include gardens planted with certain flowers to support pollinators or farmland with retained hedgerows and field margins to provide nesting habitats.

Ecosystems of this type do not hold any value in terms of a link with the past as they are not the result of an unbroken chain of evolutionary and ecological processes. They do, however, allow ecological and evolutionary processes to continue, though highly modified, and so they have some value in terms of supporting the continuation of these processes if they are assigned a moral value. There does not seem to be any ethical reason not to completely remove or destroy this kind of ecosystem if it is not contributing to wider biodiversity conservation as these processes can be easily recreated elsewhere, unlike managed nature reserves, semi-reconstructed ecosystems and pure wilderness which represent at least some level of complexity developed without human intervention and the complete reconstruction of these ecosystems is unlikely.

This does not mean that biodiversity-friendly artificial ecosystems have no moral worth and can be removed without ethical objection. The contribution to wider biodiversity mentioned above is the main source of their intrinsic value; a common aim of conservation groups is to encourage land managers and members of the public to make farms, parks, timber plantations, gardens etc. more wildlife-friendly because so much of land today is used for these purposes and these intermediate habitats are vitally important for maintaining landscape-scale biodiversity by improving habitat connectivity, providing additional habitat and increasing diversity of habitat types across a landscape. The intrinsic value of the species supported in part by this type of ecosystem means that they are an ethically supportable and realistic aim of conservation, provided that they are part of a wider system which supports other, less tangible values such as the unbroken progression of an ecosystem.

Artificial maintenance of biodiversity

Another possible option which may contribute to biodiversity conservation is maintaining species in captivity. As a conservation aim on its own, this option has several ethical problems but may have some limited value.

In this case, the intrinsic values of on-going ecological and evolutionary processes and a link with the past are lost but if the alternative is the complete extinction of a species then this aspect of conservation could be valuable in preventing this and maintaining the possibility of a reintroduction. This scenario raises an interesting question: what if, in theory, every species around today was maintained in captivity only, and all ecosystems opened up for development/destruction? What values would be lost? This does not seem like a satisfactory outcome and so some value other than biodiversity seems to be involved. This question can help being into focus the difficult to define values of allowing ecological and evolutionary processes to continue and to continue without interruption if possible.

Alternatives

New ecosystems to cope with new pressures

It is theoretically possible that entirely new ecosystems with novel species compositions could be set up which are well equipped to maintain high levels of biodiversity alongside human development. These could use new species assemblages which included non-native species. This option could only be considered if existing ecological and evolutionary processes were assigned very little value (though it could be argued that the processes would continue in a new form) and continuity of these processes was assigned no moral value. However, this would be an extremely high-risk approach as the complexities of ecosystems mean that the outcomes of deliberately introducing non-native species are hard to predict and are often disastrous, e.g. the introduction of non-native cane toads to reduce crop damage by the native cane beetle in Australia having unexpected, damaging and long-lasting results. As this method of conservation would carry such high risks and at best only maintain the basic intrinsic values of a diversity of individual species it does not seem to be an ethically supportable option.

De-extinction?

A recent hot topic, de-extinction is now being discussed as an option in conservation and not as such distant a prospect as might be imagined. Using preserved genetic material from an extinct species and a closely related or similar existing species to bring back some individuals from extinction is looking like it will be a real possibility. Last week a conference was held on this subject and the practicalities, pros and cons were discussed. If the ethics of this topic are examined purely from a conservation point of view, rather than from the point of view of the individuals of the “de-extincted” species or in terms of the potential genetic pitfalls, then de-extinction may have some value in terms of bringing back a species (with an intrinsic value) previously lost and perhaps also similar values to current species reintroductions. Less dramatically, a species not yet extinct but threatened due to low numbers and a genetic bottleneck could have genetic material from dead individuals reintroduced to the gene pool to improve their resilience. However, the costs of bringing back a few individuals are unlikely to be worthwhile in terms of biodiversity conservation when more species could be saved from extinction with the same funding, making it difficult to use biodiversity conservation as a reason to justify what may simply be a scientifically interesting exercise. The conference, speakers at which expressed the points here, was a TEDx event and can be viewed here and has a website here. This subject will probably be covered in more depth in a future post.

Conclusions

By examining the changes in intrinsic values along a spectrum of systems used to conserve biodiversity, several different intrinsic values of biodiversity and ecosystems can be demonstrated. Other than the basic intrinsic value of each species, which alone is a reason to conserve biodiversity, there seems to be some value in both the ecological and evolutionary processes, similar to that of a species, and the unbroken continuation of these processes. These additional values are gradually lost or diminished moving along the gradient from pure wilderness to captivity. This does not mean that methods of conserving biodiversity other than protecting pure wilderness should not be used – from an practical point of view they are very important in conserving biodiversity and do support the additional values to varying extents. However, which of these values conservation work is aiming to protect is not always clear, perhaps because conserving biodiversity is the most easily articulated and urgent and so additional, more abstract values are sometimes (though not always) pushed aside. It would be useful to explicitly discuss and formalise the values of processes and continuity in conservation efforts to ensure these are protected and do not slip away without their value being realised.

References

[1] Callicott JB (2003) A Critique of and an Alternative to the Wilderness Idea. In Environmental Ethics, ed. Light A & Rolston III H. Blackwell Publishing Ltd.

[2] Singer P (2011) Practical Ethics (3rd ed.). Cambridge University Press, New York, USA.

Killing in conservation: Lethal control

Animals are often deliberately killed with the aim of conserving threatened species, habitats and ecosystems. It is usually assumed that the ends justify the means and that the costs to life are outweighed by the benefits. Although lethal control measures are common practice in conservation, the ethical issues involved are not often explicitly discussed. This is not to say that these decisions are not based on ethical values, they certainly are, but these decisions are frequently made using implied ethics rather than rigorously examining the ethical issues. This post aims to identify the ethical issues involved in justifying lethal control for conservation purposes. This post is not covering  lethal control for financial gain or other non-conservation motivations (e.g. badger culls or illegal killing of birds of prey by gamekeepers), killing wild animals for conservation research (this will be a future post) or solidly suggesting where lines should be drawn, only identifying the issues which should be considered in lethal control decisions in conservation.

Equal consideration of interests versus effective conservation

The essence of this decision is the balance between the interests of individuals of the “problem species” and the conservation benefit resulting from their removal. The interests of the problem species must be given full and equal consideration and are more straightforward to determine, assuming there is no question of a threat to their conservation. This is an important assumption; the decision is much more complex if there is a possibility that the problem species is also under threat of extinction or could become threatened as a result of control measures. However, as many problem species are detrimental to other species, habitats or ecosystems as a result of their abundance, this is usually a safe assumption. Another assumption is that the problem species is not necessary for the conservation of another species, habitat or ecosystem in the proposed control area. The interests of the problem species are balanced against conservation values – the continued survival of ecosystems and the prevention of biodiversity loss. The value of an ecosystem or habitat is not the same type of value given to the interests of individuals of the problem species and so they can be difficult to weigh against each other – comparing apples and oranges. Even when the conservation interest under threat is a sole species, it is not usually correct to simply compare the interests of individuals of the threatened species with those of individuals of the problem species as the threatened species presumably has an additional conservation value.

Lethal control is not the only option to deal with a conservation threat, many other methods exist, but limited resources for conservation frequently lead to the decision that lethal control is the most efficient and effective option. Once the decision has been made that action must be taken to protect a threatened species, habitat or ecosystem, these financial considerations come into the decision to use lethal control but are not the only factors; several other issues affect the decision on whether lethal control is the most ethical solution.

Factors affecting the weight given to the interests of problem species

Intelligence and awareness

The interests of individuals of problem species largely depend on their level of sentience. This is sometimes considered in generalised terms by considering taxa, but this does not fully represent the ethical issues as species within a taxon may have a wide range of sentience levels. The issues involved in determining the weight given to the interests of a problem species include self-awareness, intelligence, rationality and the ability to view itself as a being existing through time. This topic is discussed by Peter Singer in terms of the ethics of killing animals for any reason, in a chapter entitled “Taking life: Animals” in Practical Ethics (3^rd ed., 2011) and many of the discussions can be applied to lethal control. The key issue is whether or not an animal has an interest in continuing to live. If so, this interest must be considered. All animals have evolved defensive and protective responses to certain threats to their lives but this does not necessarily mean that they view themselves as beings existing through time which wish to continue living. However, studies of several species, including primates, pigs and birds, have found that some species do have the ability to understand themselves as beings which exist over time and so potentially have an interest in continuing to live which will be violated by lethal control. This does not necessarily mean that lethal control cannot be justified but this information affects the weight given to the interests of individuals of the problem species.

 

Native or non-native

Non-native species cause many threats to conservation as they often outcompete or predate native species which have not evolved in their presence and so are unprepared to cope with this sudden new pressure. However, it should be the problem caused rather than the non-native species status alone which contributes to justifying lethal control. But does the native or non-native status of the problem species affect the weight given to the interests of individuals of this species? That is, if a similar problem is caused by a native species and a non-native species, is there more justification for controlling the non-native species than the native species? This justification may take the form of an argument for conserving an ecosystem “as it should be”, as it would have been without this non-native species. Yet ecosystems have been modified to such a degree by humans (the source of the vast majority, if not all, species introductions) that removing a non-native problem species will not result in a return to this utopian, perfect ecosystem, weakening the argument for aiming for this “natural ecosystem”. Also, if a non-native species is beneficial to conservation, such as non-native sycamores in the UK providing good habitats for native birds and invertebrates, the non-native status of the species seems little justification for removing it. Perhaps aiming for new, sustainable ecosystems with the aim of maximising global biodiversity regardless of the geographic origin of species would be a better solution – though this will often, but not necessarily, mean the removal of non-native species. So although non-native species are often problematic, there appears to be little justification for using this status as a factor justifying lethal control – though it is frequently vaguely mentioned as a factor.

 

Source of problem

The previous section mentions that humans are the source of most, if not all, problematic species introductions. Humans are also the cause of many other problems in conservation which may lead to the possibility of using lethal control. Examples include hunting natural predators to extinction or low levels (e.g. unsustainable deer populations resulting from wolves being hunted to extinction in the UK) or destroying habitats such that species, habitats or ecosystems are now threatened with extinction due to factors which were previously not a problem (e.g. the impact of predation on breeding wading birds is now possibly unsustainably high after wader populations have been reduced following massive habitat loss). As humans are the source of these problems, it may be that we have an ethical obligation to resolve them which could reduce the weight given to the interests of individuals of the problem species. (In the case of humans causing the extinction of natural predators, it could be argued that lethal control of the now problematic prey species is justified as humans are theoretically taking the place of the predators. However, the effects of killing by humans are likely to be very different to the effects of killing by natural predators unless efforts are made to kill the individuals which would be most likely to be taken by natural predators, e.g. the slowest and weakest animals. When the species being controlled is also considered to be a game animal, for example deer in the UK and the “Big Five game” in Africa, the issues are also clouded by financial and political motivations.)

Factors affecting the weight given to the threatened conservation interest

Species, habitats and ecosystems can be considered to have a variable conservation value which is given a variable weight – with the product of these two factors to be compared with the considerations of the problem species discussed above. What determines the value of a species, habitat or ecosystem and what determines the weight given to this value? 

Certain elements concerning the value of a species, habitat or ecosystem are constant across all conservation interests. These include existence value - the idea that a species should be allowed to continue to exist and evolve without being destroyed by humans (discussed in my previous post) - and heritage value – that species, habitats and ecosystems should be conserved for future generations. These values are particularly subjective. In addition to these values, other elements concerning the value of a species can be variable and generally concern their ecology. One such element is the contribution of a species to ecosystem functioning (an ecosystem function is a useful process carried out by biota, such as nutrient cycling), e.g. a keystone species, vital for the maintenance of ecosystem functioning, may be assigned a greater value than a species considered redundant as it only contributes an ecosystem function also performed by many other species. Other elements adding variable values could include spiritual and aesthetic values and ecosystem services (ecosystem functions which benefit humans, such as crop pollination) – though while these are not strictly conservation values as they are for human benefit, they are factors which are considered.

Let us assume that biodiversity has a very high value and the extinction of any species is a great evil to be avoided. The next stage is considering how great a weight to assign this value. The level of extinction risk is the main factor influencing the weight given to these conservation interests when making a decision regarding lethal control – simply that the greater the risk of extinction, the greater the weight given to the conservation value of this species. When considering the conservation value and weight given to a habitat or ecosystem, the combined conservation values of and extinction risks posed by the loss of the habitat or ecosystem to multiple species can be used. The other important factor in assigning a weight to conservation value is the size of the expected benefit – if only a small advance against extinction risk is made then the weight given to the conservation interest is reduced and vice versa. (The level of certainty that lethal control will result in this benefit is discussed below.)

Factors affecting the decision to use lethal control

If it is decided that the benefit to conservation outweighs the interests of the problem species, what affects the decision to use lethal control over non-lethal methods? (Financial considerations are one factor, but the ethics of conservation funding is outwith the scope of this post.)

 

Imbalance between interests of problem species and conservation interest

If the degree of difference between the interests of the problem species and the conservation interest is very slight, then this difference does not seem to be enough to violate the interests of the problem species. How great does the difference need to be in order to justify lethal control? If these competing interests were quantifiable, perhaps if the conservation interest were at least double that of the interests of the problem species, and so the harm of violating the interests of the problem species was made up for by the benefit of the conservation interest, then lethal control could be ethically justified. But these values are not quantifiable and are interests with very different qualities and so are difficult to compare. This does not mean that it is impossible to consider the imbalance between interests when making decisions about lethal control; this is a very important factor to consider and this difficultly means that very careful thought must be put into the weights given to both the interests of individuals of the problems species and the conservation interest.

 

Effectiveness of control measures

The level of certainty about the benefit to the conservation interest as a result of control measures is another vital factor in decisions about lethal control. It is important that the proposed measures have been thoroughly researched (this may in fact involve a lethal control trial, the ethics of which will be discussed in a future post) and that the level of certainty (highly unlikely to be 100%) that the required benefit will occur as a result is taken into account in the decision.

Alternative measures

Lethal control is considered by some to be a last resort and by others as the go-to solution. Either way, full investigation and consideration of alternative measures are sometimes not carried out. Non-lethal control measures exist which can be highly effective, ineffective, cheap, costly, understudied and/or dependent on the conditions of individual sites. Non-lethal methods must be fully considered and if a similarly effective non-lethal method can be carried out then best efforts should be made to use this method, as to use lethal control in this case would be to violate the interests of individuals of the problem species without sufficient justification. (This is the point in the decision-making process when funding considerations may become particularly influential.)

Method of control

The method of lethal control is another factor to be considered when making a decision about the use of lethal control in conservation. The main considerations are the potential of the problem species to experience pain, suffering and anxiety. The level of development of the nervous system of the problem species is an important factor for control measures with the potential to cause pain and suffering, for example using a toxic chemical which slowly kills an animal may be more justifiable when used on an animal with a very basic nervous system and limited capacity to feel pain (e.g. bivalves such as oysters or mussels) compared with animals which have a more developed nervous system (e.g. vertebrates). The additional ability of “higher” animals to feel anxiety and fear, for example when captured, contained or handled before control takes place, is also a factor for similar reasons. Efforts must be made to reduce such suffering and if some suffering is still likely to occur then this must be taken into account when making the decision about using a method of lethal control.

Conclusions

Lethal control is widely used in conservation and in many cases may be ethically justifiable, though the ethical implications are sometimes implicitly rather than explicitly explored. This may be due in part to a lack of time and resources, interest in or understanding of the ethical issues involved or not considering lethal control to be an ethical problem. The key issue is addressing the difference between the interests of individuals of the problem species and the conservation interest of the threatened species, habitat or ecosystem, followed by a decision on whether the difference between the costs and benefits justifies the use of lethal control. It is important to consider these issues to ensure that conservation is carried out in the most effective and ethical way.

Why save a species?

When justifying the conservation of species and biodiversity there are several key arguments frequently put forward. Maintaining functioning ecosystems, to ensure the provision of ecosystem services (i.e. ecosystem functions which benefit human such as removing CO₂ from the atmosphere), preventing the loss of species with potential medical benefits and aesthetic and spiritual concerns are the main reasons frequently given in scientific literature, conservation organisation media and government publications. A final reason is often given or alluded to – existence value, the idea that because a species does exist it should be allowed to continue to exist.  Does a species have a value which is not related to its benefit to humans (real or hypothetical) or interactions with other species? Many people certainly feel strongly that it is wrong to allow or cause the extinction of a species but when arguing the case alternative justifications for preventing species loss are heavily relied upon. The term “species” will be used to discuss this topic – however, the definition of a species and if this is the best level of diversity at which to conserve are debated topics.

Us and them

All of the main reasons, listed above, given for conserving species can be reduced to either those which are beneficial to humans in some way or those which concern the existence value of a species. Many of the arguments concern conserving diversity of life rather than the survival of individual species but all are ultimately underpinned by either one of these main ideas.

(Humans can be considered part of ecosystems and so perhaps the arguments cannot be divided in this way – but the extent to which humans are considered part of nature is a topic for another post!)

Conserve for human benefit

Conserving species in order to continue ensure the continued provision of ecosystem services is a reason to save species explicitly for human benefit. It does not actually support the conservation of all species, only those necessary for these services to continue plus several more species to make sure the ecosystem is robust enough to continue to provide the service despite some inevitable species losses.

Preventing extinctions to avoid the blunder of permanently losing a species with currently unknown medicinal properties is also clearly for the benefit of humans. Another human-orientated argument is conservation for aesthetic purposes, so that future generations can enjoy nature.

This does not detract from the use of these arguments to drive conservation effort; they are all important and valid points. In addition, human-based reasons may be the only arguments some will accept and the support of all kinds of people with different opinions is vital for successful conservation. But is there a greater moral reason to conserve?

Conserve for existence value?

Other arguments for saving species are more ambiguous in their motivations.

Defending conservation of species for spiritual reasons, although still orientated around human welfare, hints at a desire to care for nature as something beyond a mere resource for our use and benefit.

One of the strongest arguments for preventing extinctions is the (much debated and researched) idea that higher biodiversity results in a greater number of ecosystem functions – i.e. a more robust ecosystem which can cope with change. As with the ecosystem services argument, this reason is concerned with biodiversity rather than saving individual species. However, this argument can be split into the same two sides, human benefit and existence value. Conserving biodiversity in order to protect ecosystem functioning can be seen in one way as identical to the human benefitting ecosystem services argument. But on the other hand, “ecosystem functions” are distinct from “ecosystem services” for a reason – ecosystem services are defined as those ecosystem functions which are beneficial to humans. (Of course, the dividing line between the two is not as clear-cut as this as the complexity of ecology means it is not always obvious which functions are indirectly linked to those which we directly benefit from, but for the sake of argument we can treat them as separate motivations for conservation.)

So, to what end to we aim to protect the remaining ecosystem functions? Protecting biodiversity for the sake of robust ecosystem functioning means that more species can survive. If not humans, then the implication is that the beneficiaries of the ecosystem functioning argument are the species which could survive as a result. Here is the idea that the more species surviving, the better.

This leads to the question of existence value, the idea that because a species exists there is an ethical argument for its continued existence. Is this the case? Does anything affect this value? Does it matter if humans are the cause of the risk to a species’ survival?

The useless species

In order to illustrate the removal of all human-benefit reasons for conservation to leave only the question of existence value, an imaginary “useless species” can be used.

Imagine a species. As a species, it does no harm nor good to any other species (including humans). The ecosystem can carry on as before with or without it. This species does not deplete the numbers of any others and it not required to keep another’s population size under control. Nothing depends on it such that they could not survive as well on another species in its place. From a practical point of view, it does not matter to humans, other species, the ecosystem or the planet if this species lives or dies.

If this species is about to go extinct, is there an ethical reason to try to save it? Why? Imagine thousands and millions of these useless species – does this change anything?

Gut feelings

The origins of ethical values are complex and debated, but many if not most people feel that it is wrong to allow a species to go extinct, all other factors being equal, and feel so particularly strongly when humans have played a role in driving a species to a high-risk state. Why do we feel this way? Perhaps part of the explanation is a vague uneasiness about the finality of extinction – that it should be prevented in case a better reason is thought of after it is too late. Perhaps also because we feel that we are a part of the natural world and have a desire to protect it in a non-speciesist manner – most humans would not want our species to go extinct.

Gut instincts can be useful to help us understand why we feel an action is right or wrong but they are not an ethical argument. Is there a true ethical reason to save a species from extinction?

What is the existence value?

Existence value and the value of life

When debating the value of life, the experiences of the being and its ability to view itself as an entity with a past and future are considered, among other factors. Can these arguments be applied to a species? A species is not a conscious, pain- and pleasure-experiencing entity, the removal of which may result in a reduced level of enjoyment in the world. This may be true of the lives of individuals of sentient species but not of the species as a whole. Similarly, it is only genetics which drive the survival of species, but the fact that genetic material in a species is self-replicating is not a basis for ethical decisions about species. Genes around today are here because they evolved in a manner which caused them to survive; this does not mean that they have interests to consider. Individuals in a species may have a desire to survive but this is not true at the species level.

The way in which an extinction could result in a reduction of pleasure in the world is through its relationships with other species. One extinction is likely to have knock-on effects and could ultimately reduce the level of satisfaction and happiness of sentient beings by making survival tougher, for example through the loss of a key food source. This indicates that the value of a species is at least partly related to its role in supporting the happiness of sentient species – bringing us dangerously close to the anthropocentric arguments! However, this reasoning does not describe true existence value of a species, only additional considerations.

Taxanomic considerations

From an ethical, non-taxaist viewpoint it does not matter what kind of species is being considered, the question of an existence value remains the same. It feels different to consider the value of the useless animal than to consider the value of the useless bacteria, but this is due to the additional considerations related to the value of sentient lives and also our human-orientated aesthetic and spiritual feelings towards nature. Any existence value of a species is independent of these values.

Human destruction considerations

Extinctions happen. Species go extinct all the time in their millions and have done so since species evolved from the soup of the early Earth. In certain periods throughout the history of the planet there are mass extinction events when, for some reason or another, the extinction rate jumps significantly above the general base rate. We are currently experiencing a mass extinction event.

Does this change the existence value of a species? If a species does have a value then does it only extend to the end of the period it would have existed without the onslaught of recent human destruction? If this is the case then humans have a moral obligation to prevent the extinction of species which they have pushed to the edge of survival, because otherwise we are preventing the continued existence of a self-replicating species which has a right to continue to survive.

(NB The status of human actions as distinct from natural causes of mass extinction events, such as ice ages and meteors, is debateable!)

Pure existence value?

The above argument only suggests that if a species is assumed to have an existence value then we ought to prevent its extinction if we would be its cause. What is the essence of the existence value of a species? A species is a set of living beings which reproduce to create similar beings capable of further reproduction. Species around today have survived through many different forms and only exist in a transient state, constantly evolving. In this way a species is difficult to pin down as an entity which might have a right to survive. It is difficult also to consider the question of its continued existence without thinking of humans, the likely cause of its extinction.

Does a species as it exists at a given time have a right to survive? This right must be limited to the difficult to define or determine “natural lifespan” of the species as otherwise there would be a moral obligation to prevent any species extinction, including those which would have occurred anyway, and the world would be overrun with immortal species. Perhaps it has a right to continue to exist simply because it has done so, but why? Here is where this train of thought ultimately leads and so this discussion is not over – I would really welcome any opinions on this topic!