The Galapagos Islands are a group of volcanic islands approximately 1000 km off the coast
of Ecuador. The water in the archipelago is protected by the 138 000 km2 big Galapagos Marine Reserve (GMR). A combination of environmental factors contribute to the unique physical environment of the islands. Situated in the eastern Pacific on the Equator the Islands are in the intersection of several ocean currents that mix cold and nutrient rich deep water through the forces of upwelling with warm tropical water. This results in a predominantly dry subtropical climate. Due to different directions of the currents the temperature, salinity and supply of nutrient varies across
the archipelago (Boje and Tomczak 1978, pp181-200). The islands are periodically exposed to El Nino events that stops the upwelling and results in increased water temperatures and heavy rainfall. The geological features provide several coastal and marine habitats including sandy beaches, rocky shores, coral reefs, submarine mountains, ridges and valleys (Galapagos Conservancy 2018)
The marine coastal waters of Galapagos hold up to 20% endemic species (Galapagos Conservancy 2018). The special conditions supports both warm and cold water species. The rocky intertidal and subtidal shores of the Galapago Islands is made up of primarily volcanic material and holds a rich ecosystem. The subtidal rocky reefs accounts for approximately 90% of the subtidal habitats around the islands (Kaplan et al. 2014, pp 1512).
Due to the great variation in conditions this ecosystem is can be subdivided into three or five major biogeographical regions consisting of the far northern area, central/south-eastern area and western area. If divided into five regions, Elizabeth and the Northern part is included (Edgar et al. 2004, pp 1107). The primary production of this ecosystem is from planktonic production from the nutrient-rich deep water provided due to upwelling as well as benthic production. High biomasses of small pelagic fishes and suspension-, filter- and grazing feeding invertebrates are present. Omnivorous and reef-dwelling fishes as well as predatory invertebrates are present. The ecosystem provides feeding ground to the green sea turtle and the endemic marine iguana. A variety of high level- and top predators are present in the habitat, some live there while some visit to feed. These include octopus, the endemic Galapagos penguin, the endemic Galapagos sea lion, several species of sharks, whales, rays, tuna, dolphinfish, billfishes among others (Okey et al. 2004, pp 386)
The archipelago also holds some coral reef ecosystems. These occur in microhabitat with suitable coral conditions, are fairly small in size and scattered across the islands
Approximately 20 species of reef-building corals and around 30 species of non reef-builders exist around the islands (Feingold & Glynn 2014, pp 6).
The ecosystem holds 25 species of corallivory fish and also provides habitat for some fish species (Glynn et al. 2018, pp 725).
3. Ecological condition of the main ecosystems
Due to high endemism and specialisation many species in the Galapagos archipelago the ecosystems are highly vulnerable of external factors like human or natural stressors (Vinueza et al. 2014, pp 89).
The habitat of the rocky reef ecosystem has undergone big transformation since the El Nino event 1982-1983 and many species have not recovered since. Many species that were considered threatened are now only found in isolated areas in the western region. Correlation of fishing pressure and loss of lobster and large predatory fishes have been seen close to fishing ports. Loss of predators like lobsters and reef fishes may be a contributing factor to increased grazing pressure by sea urchins observed. The loss of macroalgae and corals might be due to the increase grazing pressure (Glynn et al. 2018, pp 717-733). Top predators like sharks are in danger of being killed through by-catch although it is prohibited target sharks, many of them are listed as vulnerable by IUCN. Over the last decade local divers have reported a decline in shark numbers. Some of the threats to the ecosystem are tourism, invasive species, fishing, land- and ocean based impacts and climate change (Hearn et al. 2014, pp 23-26)
The coral and coral reef ecosystems have been subject to several events and factors leading to coral tissue loss. These include El Nino and La Nino events, bioerosion and loss of recruitment. During the El Nino event in 1982-1982 led to a mortality in corals around 95%. Some recovery has been seen between events but in general the big majority of the reefs have undergone degradation. Similar trophic cascade to that of rocky reef ecosystem has been observed in the coral reef ecosystem due to overfishing of lobsters and big predators, magnifying abiotic events like El Nino. (Glynn et al. 2018, pp 717-733) Generally the ecosystems functionality is endangered due to factors like maintaining ecological resilience, maintaining carbonate substrate enforced by overall lower pH in the ocean, surviving species adjusting to higher temperatures and decline of coral cover (Feingold & Glynn 2014, pp 13-14)
Human development and impact
Between 1990 – 2014 the Galapagos population increased from 10 000 to 30 000. The rise in population is mostly due to a major growth in the tourist sector with around 40 000 visitors in 1990 to around 200 000 in 2014 (Denkinger & Vinueza 2014, pp viii) The population density of the islands is 3,7 inhabitants/km2. Due to the growth of population, visitors in the archipelago and fishing pressure the ecosystems are subject to the coastal development including sewage, invasive species, tourism, littering, overfishing, boat traffic and oil spill to name a few. Tourism is a big part of the economy if Galapagos. Apart from the factors mentioned above the increase in tourism is likely to contribute to destruction of habitat that is more or less direct outcomes of tourism. An indirect effect of tourism is the increased need for food that contributes to further fishing pressure (Vinueza et al. 2014, p 83, 93)
Fishing is conducted within and around the Galapagos marine reserve. Within the reserve only small scale local fishing is allowed. Overexploitation of specific species has led to decrease in numbers, sea cucumber and lobsters among other. These practices has had great effect on marine habitats (Maddock 2015). The waters outside GMR are subject to industrial fishing and illegal fishing within the borders of the reserve occur. The shark fin market contributes to illegal fishing practices although sharks are protected within the reserve (Hearn et al. 2014, pp. 24). By-catch is considered to contribute to overfishing and finfish fishing is not regulated (Zimmerhackel et al. 2015)
The same activities, mainly tourism and fishing, that affect the ecosystem of the area are also dependent on the ecosystems well-being. The ecosystems provides marine resource livelihood and local small scale fisheries are dependent on them. In terms of tourism the local economy is reliant on it and the ecosystems provide the opportunity of activities like diving, snorkeling, kayaking etc (Vinueza et al. 2014, p 83)
C. Details of the environmental management applied to the area, if any
The Galapagos Marine reserve was created in 1998 and the main purpose was to “protect and conserve the coastal-marine ecosystems of the archipelago and their biological diversity for the benefit of humanity, the local population, science and education” (GNPS quoted in Jones 2012, pp 68). The Management plan contains specific objectives including the long term conservation of: marine and coastal habitats, vulnerable and endemic species as well as management of their recovery if needed. It also includes social objectives focused on support of local fishing activities that are harmonious with the conservation of biodiversity as well as conserving the ecosystems that are the natural capital of the tourist sector (Jones 2012, pp 68). To reduce conflict between stakeholders the coastal zones have been divided into zones of conservation and no permission of tourism nor fishing (6%), conservation and tourism but no fishing (11%), artisanal fishing zones (77%) and unallocated areas for future division (5%). These zones are considered preliminary until further data on biodiversity and resources is retrieved (Edgar et al. 2008, pp 956).
In 2014 a new management plan for protected areas of Galapagos was developed. It is perceived as a management instrument with the emphasis on Galapagos as a socioecosystem and the vision “the Galapagos province achieves good living for the human community by preserving terrestrial and marine ecosystems and their biodiversity through a regional model that integrates protected areas with populated areas” (DPNG quoted in Calvopiña et al. 2015, pp 13) . The plan recognises that conservation and development in Galapagos is not in opposition to each other but rather interconnected (Calvopiña et al. 2015, pp 15).
D. An assessment of the effectiveness of the management plan in meeting its objectives.
The status of the biodiversity has not been thoroughly assessed in GMR. The prohibition of industrial fishing in the reserve has lessened fishing pressure of some top predators including sharks and tuna. Some illegal fishing still occurs in the waters of the reserve. Previously common catch like sea cucumber, spiny lobster and groupers by the local fisheries has seen a long term decline, also during the period of implementation of GMR (Jones 2012, pp 70). The archipelago with its complex geography in combination with non-existing indications on praxis where different use-zones are intersecting contributes to confusion of enforcement and low compliance by stakeholders (Moity 2018, pp 2). Currently only 1 % of the whole area is protected by no-take zones and ineffective enforcement has led to over extraction of marine resources (Sustainable Fisheries Group UCSB n.d).
However, new re-zoning has led to a new no-take zone in 2016 around the islands of Darwin and Wolf in the north. These islands hold a great biomass of reef fish including sharks and the announcement is a step in the right direction (Harvey 2016). The overall health of the marine ecosystem in GMR is facing challenges posed by tourism, fishing pressure including local and industrial fisheries as well as illegal fishing and climate change induced effects despite GMR protection.