Henkens, R.J.H.G.

Mountain biking on Aruba's wild coast

The island of Aruba predominantly has a ‘sun, sea and sand’ tourism destination image. The Arub Tourism Authority (A.T.A.) aims to diversify the Aruban tourism product by developing tourism niche markets. One of the opportunities lies in the development of mountain biking (MTB), which is considered a popular and growing sport amongst tourists and locals. In November 2018, the A.T.A. received a proposal from an experienced trail building company in Colorado (USA) titled: Aruba MTB Trails. Developing a niche market for mountain biking in Aruba. The proposal aims to design and build some 54 km of bike optimized MTB trails.

Although the plan matches with the ambitions of A.T.A., the Authority questions whether the plan is really as sustainable as stated in the proposal. This environmental impact assessment (EIA) assessed this issue by answering following research questions:

  • What are the impacts of the proposed MTB-trails on the (ecological) environment in the project area?
  • What are the cumulative impacts (indicative) of other user groups on the (ecological) environment in the project area?
  • What measures should be implemented to mitigate or compensate any ecological impacts assessed?

These questions were answered based on a thorough literature study, a field visit in November 2019, a field study of the Aruban Burrowing Owl and interviews with local stakeholders and experts. It could be concluded that: The proposed MTB-network is, in theory, an improvement for the ecological environment when compared with the present MTB-network, though additional measures are needed before speaking about a ‘sustainable’ MTB-network.

The length of the present 50+ km MTB-network is not so much different from the proposed MTBnetwork. The main difference lies in the fact that MTBs are assumed not to ride off-road anymore in the proposed situation. Off-road riding leads to the creation of informal roads and paths and results in soil erosion, habitat degradation and fragmentation, nest disturbances and (fatal) collisions with (ground) breeding birds and snakes, which are the most vulnerable species groups. Some of these impacts were observed while visiting the area.

In the proposed situation there are still species that would show moderate or substantial vulnerability to MTBs. This has to do with the fact that proposed MTB-trails are too close to potential breeding habitat of the Aruban Burrowing Owl and Least Tern as well as the potential for MTBs to collide with snakes between dusk and dawn. This requires rerouting of the proposed MTB-trails (spatial zoning) or closure of ‘problem’ trails at least during the most vulnerable months (breeding season owls and terns) or time of day (between dusk and dawn). These measures indicate, among others, that a trail network within the Tierra del Sol nature area, which is a stronghold for the endangered Aruban Burrowing Owl, is not realistic. Our use of ‘in theory’ in the conclusion above is intentional, as the sustainability-issue goes much further than the MTB-network. The main conclusion of this ecological impact assessment is therefore that: Sustainable development of Aruba’s wild north coast, can only be achieved with a nature and visitor
management plan (including MTB) for the area as a whole, that matches with the ambitions in Aruba’s Spatial Development plan 2019.

Present ecological impacts in the project area are substantial and concern habitat loss and fragmentation, damage to vegetation and soils, disturbance of fauna and to a lesser extent also the loss of individuals due to collision and pollution. Though these impacts can partly be attributed toMTBs, it is nothing when compared to the cumulative impacts of the multiple ATVs and UTVs which dominate the area (especially the lower terrace) with their numbers, speed, noise, off-road driving erosion and dust creation. The scope of these impacts goes beyond the project area and does not only relate to the ecological carrying capacity but also to the social (local community) and even psychological carrying capacity (tourists).

This situation is contradictory to the Aruba Spatial Development Plan 2019. This plan classifies the project area in two categories nature (e.g. Tierra del Sol) and nature and landscape with characteristics like silence, low-impact visitor-use, driving on formal paths and roads as well as restoration, conservation and development of natural values. This contradiction confirms the selfevaluation by the Ministry of Nature and Environment (Min. ROIM, 2018) in which the lack of law enforcement for the conservation of nature is regarded as one of the weaknesses, while not taking into account the ecological carrying capacity of Aruba risks the creation of an unlivable environment for generations to come. These observations make clear that sustainable development of the project area can only be achieved with a nature and visitor management plan for the project area as a whole. A list of 15 actions and measures is included in this report, which it is recommended should be integrated within the nature- and visitor management plan.

Data type
Research report
Research and monitoring
Report number
Geographic location

Staat van de natuur van Caribisch Nederland 2017


Sinds de staatkundige herstructurering van het Koninkrijk in 2010, maken de Caribische eilanden van Bonaire, Saba en St. Eustatius als speciale gemeenten formeel deel uit van Nederland. Het Ministerie van Economische Zaken (sinds eind 2017: Ministerie van Landbouw, Natuur en Voedselkwaliteit) heeft daarmee de eindverantwoordelijkheid voor de uitvoering en implementatie van een zevental internationale natuurbeschermingsverdragen voor de eilanden. Deze verantwoordelijkheden houden verplichtingen in en leiden tot verschillende beleidsvragen. Om hieraan invulling te geven wordt eens in de vijf jaar een natuurbeleidsplan opgesteld en wordt er gerapporteerd in het kader van de Convention on Biodiversity (CBD) en het Specially Protected Areas and Wildlife (SPAW) protocol van het Cartagena Verdrag maar er wordt niet gerapporteerd door middel van een “natuurbalans” zoals in Europees Nederland. Voor de evaluatie van het gevoerde natuurbeleid en het opstellen van nieuwe natuurbeleidsplannen is echter rapportage over de staat van de natuur essentieel. Als maat voor de “staat van de natuur” hebben we een methodiek gebruikt die zoveel mogelijk aansluit op de staat van instandhouding (SvI) conform de Habitatrichtlijn (HR).

Caribisch Nederland maakt onderdeel uit van de Caribische “biodiversity hotspot” met een zeer hoge biodiversiteit en hoge menselijke druk. De hoge biodiversiteit uit zich in het voorkomen van zeer veel endemische soorten (soorten met een zeer klein verspreidingsgebied) en de hoge menselijke druk uit zich in veel bedreigde soorten. Caribisch Nederland telt ongeveer 130 endemische soorten en 143 internationaal bedreigde soorten van beleidsrelevantie (bijlage 1).

In deze opdracht wordt door 33 deskundigen en natuurbeheerders gerapporteerd over de SvI van een selecte groep habitats en soorten of soortgroepen (bedreigde, sleutel- en indicator-soorten) waarvoor over voldoende kennis wordt beschikt. Als maat voor de SvI van de natuur hebben we een methodiek gebruikt die zo nauw mogelijk aansluit op de methodiek voor de bepaling van de SvI zoals gehanteerd in de HR. Daarnaast wordt ook een probleemanalyse gegeven van mogelijke oorzaken en aanbevelingen gedaan voor managementoplossingen. Vanwege de structurele achterstand in kennis en monitoring van het grootste deel van de Caribisch Nederlandse biodiversiteit was een kwantitatieve rapportage voor de meeste soorten en soortgroepen niet mogelijk. 


Keywords: staat van instandhouding, natuur, habitats, soorten soortgroepen, Caribisch Nederland. 

Referenced in Bionews Special Edition: State of Nature Caribbean Netherlands

Data type
Research report
Education and outreach
Research and monitoring
Report number
Wageningen University & Research Rapport C086/17
Geographic location
Saba bank
St. Eustatius

Sixth National Report of the Kingdom of the Netherlands


The Convention on Biological Diversity (CBD) is an international treaty that was initiated by the United Nations Environment Programme (UNEP). It is ratified or accepted by 196 parties that are mostly countries. The Netherlands, but also the European Union are parties of the CBD. The CBD entered into force on 29 December 1993 and has 3 main objectives:

1. The conservation of biological diversity.

2. The sustainable use of the components of biological diversity.

3. The fair and equitable sharing of the benefits arising out of the utilization of genetic resources.


The Strategic Plan for Biodiversity 2011–2020, was agreed at the tenth meeting of the CBD Conference of Parties (COP10) in Nagoya, Japan in 2010. The Strategic Plan includes five interdependent Strategic Goals and a set of 20 Aichi Biodiversity Targets, most with an end-point of 2020. The strategic plan ultimately aimed at achieving a 2050 vision of a world where biodiversity is valued, conserved, restored and wisely used, maintaining ecosystem services, sustaining a healthy planet and delivering benefits essential for all people.


The sixth national report is used by the Conference of the Parties to assess the status of implementation of the Convention on Biological Diversity. It will provide information for a global biodiversity outlook of progress towards the implementation of the Strategic Plan for Biodiversity 2011-2020 and progress towards the Aichi Biodiversity Targets. The sixth national report guidelines request Parties to report on 1. national targets, 2. main measures, and 3. effectivity of these measures and 4. progress to achieve national targets and 5. progress to achieve the Aichi-Biodiversity targets.


Key messages

There has been significant and reasonable progress towards meeting the national targets. However, the 2020 deadline will not be reached. The path to sustainability and reaching the targets is long. The main measures are considered partly effective. The National Ecological Network, being the cornerstone of biodiversity conservation in the Netherlands is for instance still in progress until 2027, while environmental impacts, especially from agriculture are still a major concern.


Nevertheless, there has been significant progress towards meeting several components of the majority of Aichi Biodiversity Targets. Some target components, such as conserving at least 17 per cent of terrestrial and inland water areas, have been met. However, in most cases this progress is insufficient to fully achieve the 2020 targets.


The Kingdom of The Netherlands also includes six islands within the Caribbean Islands Biodiversity Hotspot, with among others tropical rainforests, coral reefs and hundreds of endemic and threatened species. The islands ecosystems are fragile. Most habitats are small as are the species populations that depend on it, while the threats are high. Most Aichi targets are not on track due to local threats from a.o. free roaming grazing livestock, pollution, invasive species and overfishing. It makes the islands ecosystems less resilient to the major threat of climate change. The island economies are very much dependent on ecosystem services, like for the tourism and fishery sectors. Despite that, the actions to deal with these local threats (if any) are generally insufficient. This is illustrated by the fact that the development on five of the Aichi-targets shows a worsening trend, while no significant change can be observed for 50% of the targets at some of these islands.

National targets and main measures

In 2011 the EC adopted a strategy to halt the loss of biodiversity and ecosystem services in the EU by 2020. The Netherlands has committed itself to nature objectives from the European biodiversity strategy and consequently the Convention on Biological Diversity. The national targets are therefore based on the European targets and related to the Aichi Biodiversity Targets (appendix 2). The 6 main targets of the Kingdom of the Netherlands in Europe are:

  1. By 2020, the assessments of species and habitats protected by EU nature law show better conservation or a secure status for 100 % more habitats and 50 % more species.
  2. By 2020, ecosystems and their services are maintained and enhanced by establishing green infrastructure and restoring at least 15 % of degraded ecosystems
  3. By 2020, the conservation of species and habitats depending on or affected by agriculture and forestry, and the provision of their ecosystem services show measurable improvements
  4. By 2015, fishing is sustainable. By 2020, fish stocks are healthy and European seas healthier. Fishing has no significant adverse impacts on species and ecosystems
  5. By 2020, invasive alien species are identified, priority species controlled or eradicated, and pathways managed to prevent new invasive species from disrupting European biodiversity.
  6. By 2020, the EU has stepped up its contribution to avert global biodiversity loss.


The 6 main measures of the Kingdom of the Netherlands in Europe are:

  1. Create new habitat within the National Ecological Network (NEN) aiming for the development of

unfragmented viable species populations

  1. The Nature Conservation Act, an important instrument to protect species and habitats
  2. Subsidy for nature management measures important to maintain biodiversity
  3. Programmatic Approach to Nitrogen (PAN)
  4. Stimulating sustainable use of natural capital and mainstreaming nature for the benefit of

society and the economy

  1. Utilising the self-organising ability of society by stimulating, facilitating and financially support

green initiatives.


In the last seven years the Dutch government decentralised responsibilities of realization and management of nature to the provinces. In 2013 ambitions towards 2027 were agreed upon in the so called Nature Pact between the national government and the provinces, including extension of the NEN, management of nature and environmental conditions, improving the system of nature management by farmers and more cross-sectoral strategies to integrate nature management with other spatial functions.


Main measures and there effectivity

The above six main measures are taken to achieve the six national targets. However, they are not directly related to one target but contribute to the achievement of several targets (appendix 2). A contribution to several targets at the same time is in theory contributing to the success of a measure. However, these interactions between measures and targets together with complex causal relations in ecology, made it difficult to assess whether measures taken have been effective. The results below show however that progress has been made and the measure is contributing to several targets. The targets however, are not met in 2020. The tools or means (indicators and monitoring) for assessing progress of national targets is described in appendix 3. The obstacles and scientific and technical needs related to the measure taken are described in appendix 4. Based on the results and indicators described below, the complex relations, the progress towards the targets and based on our expert knowledge, we conclude that the measures taken have been partially effective (table 1).





Data type
Other resources
Geographic location
St. Eustatius
St. Maarten