Background: the PSSA framework and Malpelo’s place in it
A Particularly Sensitive Sea Area is a sea area that the International Maritime Organization recognizes as needing special protection through IMO action because of its ecological, socio-economic or scientific value and its vulnerability to damage from international shipping. The operative instrument today is Assembly Resolution A.982(24) of 1 December 2005, the Revised Guidelines for the Identification and Designation of Particularly Sensitive Sea Areas, as later amended by Resolution MEPC.267(68). Malpelo was designated under the earlier guidelines, Assembly Resolution A.927(22) of 29 November 2001, which were in force when the Marine Environment Protection Committee considered the Colombian submission. A coastal state proposes the designation, documents the case under three criterion families (ecological, socio-cultural and economic, scientific and educational), and pairs it with one or more Associated Protective Measures (APMs) drawn from existing IMO instruments. Without an APM a PSSA is an awareness label; with a binding APM it is an enforceable regime.
Malpelo holds a specific place in the PSSA list. It was designated by Resolution MEPC.97(47) on 8 March 2002. Malpelo followed the Great Barrier Reef PSSA (1990) and the Sabana-Camaguey PSSA of Cuba (1997); designated on 8 March 2002, it preceded the Wadden Sea PSSA later that year, the Galapagos PSSA (2005) and the Tubbataha Reefs PSSA (2006). Among the designations of the early 2000s Malpelo is the smallest in land area and one of the most remote, and its single APM, an area-to-be-avoided, makes it one of the cleanest illustrations of how a PSSA actually constrains ship movement.
The Malpelo case is unusual in its motivation. Most PSSAs answer a pollution or collision threat from passing merchant traffic: oil tankers near a reef, ferries near a cetacean ground. Malpelo’s primary threat was illegal fishing. Colombia proposed the PSSA and the area-to-be-avoided partly as a tool to keep fishing vessels off a remote bank that the national authorities could not patrol continuously. The ATBA names fishing vessels first and all other ships above 500 GT second, the reverse of the emphasis at the Galapagos PSSA, where the merchant transit between the Panama Canal and the South Pacific drove the design.
Geography: a basalt pinnacle 500 km offshore
Malpelo is a single rocky island and a scatter of satellite rocks in the open Pacific, about 500 km west of the port of Buenaventura on the Colombian mainland and roughly 380 km from the nearest point of the coast. It is not part of an archipelago in any normal sense: the next significant land is Cocos Island (Costa Rica) some 360 km to the north and the Galapagos some 720 km to the south-west. The isolation is the point. A pelagic predator that wants a cleaning station, a current-swept seamount, or a resting bank in the middle of the Eastern Tropical Pacific has few options, and Malpelo is one of them.
The island itself is small. It runs about 1.5 km north to south, covers roughly 1.2 square kilometers of land, and rises to a sharp ridge, the Cerro de la Mona, at about 300 to 360 meters. It is barren rock, an exposed crest of the Malpelo Ridge, a volcanic structure of Miocene basalt on the Nazca and Cocos plate boundary zone. There is no fresh water, no beach, and no permanent civilian population. A small Colombian Navy detachment occupies a single building, which doubles as the only structure on the island and the forward base for sovereignty and enforcement.
What makes Malpelo a conservation priority is the water column and the seabed around it, not the rock. The island drops steeply into deep water, and within a few hundred meters of the shore the depth exceeds 200 meters, falling to several thousand meters across the surrounding basin. The combination of a small hard substrate, steep walls, deep-water caves, and the nutrient supply from the Equatorial Undercurrent and local upwelling produces a concentration of pelagic life out of proportion to the island’s size.
The Malpelo Fauna and Flora Sanctuary
The whole sea area was declared the Malpelo Fauna and Flora Sanctuary (Santuario de Fauna y Flora Malpelo) by Colombia in 1995, administered by Parques Nacionales Naturales de Colombia under the Ministry of Environment and Sustainable Development. The sanctuary is a no-take protected area: commercial and artisanal fishing are banned across the whole reserve, distinguishing Malpelo from many marine parks that permit zoned or seasonal fishing. The reserve covers about 857,150 hectares, which makes it the largest no-fishing zone in the Eastern Tropical Pacific by the figures cited in the UNESCO documentation.
The sanctuary was inscribed on the UNESCO World Heritage List on 12 July 2006 under natural criteria (vii) and (ix). Criterion (vii) recognizes superlative natural phenomena and areas of exceptional natural beauty: the undersea cliffs, the deep walls and the shark aggregations. Criterion (ix) recognizes outstanding examples of ongoing ecological and biological processes: Malpelo functions as a reservoir and a connectivity hub for large pelagic predators across the Eastern Tropical Pacific. The World Heritage property boundary is the sanctuary boundary, so the conservation designation, the no-take rule, and the World Heritage value share one perimeter, which is unusually clean from a management point of view.
The conservation regime on the water is delivered by Parques Nacionales Naturales in partnership with the Fundacion Malpelo y Otros Ecosistemas Marinos (the Malpelo Foundation), a Colombian non-governmental organization that has financed monitoring, research dives, and enforcement support since the late 1990s. The arrangement matters because Malpelo’s distance from the mainland makes continuous state presence expensive; the foundation’s contribution to vessel time and scientific monitoring fills part of the gap.
The sanctuary status, the World Heritage inscription, and the IMO PSSA are three separate legal instruments addressing the same place. The sanctuary is Colombian domestic law; the World Heritage listing is the 1972 World Heritage Convention; the PSSA is an IMO designation under the PSSA Guidelines. They reinforce one another but do not substitute for one another, and only the PSSA’s area-to-be-avoided reaches foreign-flag ships in transit under an IMO instrument.
Ecological criteria: sharks, deep water, endemism
Malpelo’s PSSA case rests on the ecological criterion family of the PSSA Guidelines, and within it on critical habitat, uniqueness, productivity, and aggregation value. The headline is the sharks. Malpelo hosts schooling scalloped hammerhead sharks (Sphyrna lewini) in aggregations counted in the hundreds, with reported counts ranging from around 200 to several hundred animals at peak, and very large schools of silky sharks (Carcharhinus falciformis) numbering into the thousands. Whale sharks (Rhincodon typus) pass through seasonally, and Galapagos sharks (Carcharhinus galapagensis) are resident. The scalloped hammerhead is listed as Critically Endangered on the IUCN Red List and the silky shark as Vulnerable, which sharpens the conservation stakes for an aggregation site that concentrates both.
Malpelo is also one of the few places on Earth where the short-nosed ragged-tooth shark (Odontaspis ferox, the smalltooth sand tiger) has been reliably observed and filmed at depth. Sightings at around 130 to 400 meters on the deep walls have made Malpelo a reference site for that poorly known deep-water species. The deep-water ecosystem more broadly, the steep walls, the caves, and the cold upwelled water, is itself a criterion: it supports assemblages rarely accessible elsewhere and links the photic-zone aggregations to the deep basin.
The endemism criterion covers both the terrestrial and the marine biota. The island’s bare rock supports endemic land animals adapted to a seabird-dominated, guano-rich, water-scarce environment, including the Malpelo lizard (Diploglossus millepunctatus) and endemic geckos and crabs, alongside large seabird colonies, particularly Nazca and brown boobies. The boobies sustain the lizards, which scavenge dropped fish and eggs, in a closed terrestrial food web that runs on the seabird colony rather than on any vegetation the dry rock could support. Underwater, the isolation has produced endemic and range-restricted fishes and invertebrates, and the steep volcanic walls carry a hard-substrate community quite unlike the soft-bottom assemblages of the surrounding deep basin.
The scientific and educational criterion is satisfied by Malpelo’s long use as a research site for shark behavior, deep-water observation, and Eastern Tropical Pacific connectivity studies, and by the World Heritage recognition that codifies that value internationally. Productivity is supplied by the upwelling that draws nutrient-rich water to the bank: the island and its ridge deflect the deeper Equatorial Undercurrent upward, bringing cold, nutrient-rich water into the photic zone and feeding the plankton bloom that the small pelagic fish exploit and the predators in turn. That is the mechanism behind the aggregations. The sharks are not drawn to the rock for its own sake but to the concentration of prey and to the cleaning stations that the bank provides, and the no-take rule protects the prey base as much as the predators.
A point that practitioners and conservation officers should hold onto is the vulnerability profile. Aggregation sites concentrate animals into a small, predictable area, which is exactly what makes them productive to protect and lucrative to poach. A single long-liner working the edge of a hammerhead school can remove a disproportionate share of a Critically Endangered population in one trip. The PSSA and the no-take reserve answer that concentrated vulnerability with a concentrated boundary, which is the logic that ties the small ATBA box to the outsized ecological stakes.
Sovereignty, the name, and a 200-mile shadow
Malpelo matters to Colombia for a reason that has nothing to do with sharks: the island generates an enormous maritime zone. Under UNCLOS, an island that can sustain its own claim projects a territorial sea, a contiguous zone, and an exclusive economic zone out to 200 nautical miles. A rock 500 km offshore therefore throws a 200-mile circle of EEZ across a slice of the open Pacific that Colombia’s mainland coast could never reach, and it gives Colombia rights over the fishery and the seabed across that water. The conservation case and the sovereignty case point the same way: keeping foreign fishing vessels off Malpelo protects both the shark aggregations and the Colombian resource claim, and the area-to-be-avoided serves both ends at once.
The name records how the island first struck the people who saw it. “Malpelo” traces to a Latin root for inhospitable, and Spanish navigators applied it in the sixteenth century to a barren, waterless crag with no anchorage and no shelter. For four centuries that hostility kept the island empty. There was no settlement, no fishing station, and no reason to call except to fix a position, because nothing on the rock could keep a person alive without supply from the mainland.
The modern presence is military and recent. Colombia established a small garrison on Malpelo in 1986 to assert sovereignty in a part of the Pacific where unmarked remoteness invites competing claims and unregulated use. The single building on the island remains the only structure, and the personnel rotated through it are the permanent face of Colombian authority over the sanctuary. That garrison, modest as it is, underpins the enforcement of both the no-take rule and the IMO area-to-be-avoided: the state that polices the bank is physically present on it.
Resolution MEPC.97(47): the designation
The Colombian submission was considered by the Marine Environment Protection Committee and adopted at MEPC 47 as Resolution MEPC.97(47) on 8 March 2002, identifying the sea area around Malpelo Island as a Particularly Sensitive Sea Area. The resolution recites the ecological, socio-economic and scientific case, identifies the boundaries of the protected area, and adopts the area-to-be-avoided as the single Associated Protective Measure.
The dual-track IMO architecture applied. A PSSA whose APM is a routeing measure needs the routeing measure adopted under SOLAS Chapter V Regulation 10 by the Maritime Safety Committee on the recommendation of the navigation sub-committee, while the PSSA designation itself is adopted by MEPC under the environmental track. For Malpelo the area-to-be-avoided was processed as a new routeing measure and brought into force as part of the IMO ships’ routeing system, reproduced in the IMO Ships’ Routeing publication and on the navigation charts that cover the Colombian Pacific. The routeing measure is what gives the ATBA legal reach against foreign-flag ships; the MEPC resolution supplies the ecological recognition that justifies it.
The implementation followed the standard sequence: adoption, a lead time for chart correction by national hydrographic offices and the publishers, notice to mariners, and integration into commercial route-planning systems. Because Malpelo carries no merchant traffic of its own and lies off the main great-circle tracks, the chart-correction burden on commercial operators was light compared with a congested PSSA like the Wadden Sea or Western European Waters.
The area-to-be-avoided: geometry and threshold
The single Associated Protective Measure is an area-to-be-avoided that all fishing vessels and all other ships above 500 gross tonnage should avoid. The area is drawn as a rectangle around the island, bounded by four corner positions:
- A: 04 degrees 04.8 minutes North, 081 degrees 43.3 minutes West
- B: 04 degrees 04.8 minutes North, 081 degrees 28.1 minutes West
- C: 03 degrees 52.15 minutes North, 081 degrees 28.1 minutes West
- D: 03 degrees 52.15 minutes North, 081 degrees 43.3 minutes West
The box runs about 15 minutes of longitude east to west and about 12.6 minutes of latitude north to south. At roughly 4 degrees North a minute of longitude is close to a nautical mile, so the ATBA is approximately 15 nautical miles wide and 12.6 nautical miles tall, an area of order 190 square nautical miles centered on the island. That is small by PSSA standards, which suits a single point feature with steep walls: the protection only has to keep ships off the bank and out of the immediate sanctuary water, not divert a shipping lane.
Two features of the threshold deserve attention. First, the measure names fishing vessels of any size as well as ships above 500 GT. Most ATBAs apply only above a gross-tonnage floor and leave small craft to domestic rules; Malpelo’s ATBA reaches every fishing vessel because illegal fishing, not merchant pollution, was the threat that drove the design. Second, the 500 GT floor for other ships is the conventional SOLAS Chapter V routeing threshold, the same band used at Galapagos and across many IMO routeing measures, and it aligns with the gross-tonnage triggers for SOPEP under MARPOL Annex I Regulation 37 and for ISM Code applicability to cargo ships.
An area-to-be-avoided is, in IMO terms, a recommendatory routeing measure: ships “should” avoid it. That word does real work in the law and is the subject of the limitations discussion below. In practice, a ship that enters the ATBA also enters Colombian sovereign or sovereign-rights waters and a no-take sanctuary, so the ship faces Colombian enforcement on top of the IMO measure, and that combination is what gives the Malpelo ATBA its teeth.
Why an ATBA and not a discharge or reporting measure
The PSSA Guidelines offer a menu of Associated Protective Measures: areas-to-be-avoided, no-anchoring areas, traffic separation schemes, mandatory or recommendatory ship reporting under Regulation 11, recommended routes, and, where a parallel MARPOL Special Area applies, discharge restrictions. Colombia chose only the ATBA. The choice tracks the threat.
Malpelo has no resident shipping, no port, and no bunkering supply chain of its own, so a discharge regime or a ship-reporting net would have addressed traffic that mostly does not exist. The Eastern Tropical Pacific is not a MARPOL Annex I oil Special Area, so the PSSA could not borrow Special-Area discharge limits the way a Mediterranean or Baltic PSSA can. What Malpelo needed was a clear, charted, legally recognized circle of exclusion that let Colombia tell a fishing vessel, or a passing ship of size, that it had no business inside the bank. The ATBA delivers exactly that and nothing more, which is why Malpelo is a textbook case of fitting the APM to the vulnerability rather than stacking measures for their own sake.
The contrast with Sabana-Camaguey, where Cuba relied on advisory routeing and domestic zoning without a binding ATBA, is instructive. Malpelo went the other way: one measure, but a hard, charted, IMO-recognized boundary backed by domestic no-take law. The result is a more enforceable regime over a far smaller area.
Enforcement: the Colombian Navy and a single building
The PSSA, the sanctuary, and the World Heritage value are only as good as the enforcement on a bank 500 km from the coast. Day-to-day presence comes from the Colombian Navy (Armada de Colombia), which maintains the small detachment on the island and patrols the surrounding water with naval and coast-guard assets, supported by Parques Nacionales Naturales rangers and by the Malpelo Foundation’s vessel time. The distance is the binding constraint. A single patrol sortie from Buenaventura is a multi-day commitment, and continuous coverage of a 190-square-nautical-mile box plus its approaches is not feasible with the assets available, so enforcement relies on a mix of physical presence, satellite and vessel-tracking data, and the deterrent value of the charted ATBA.
The illegal-fishing pressure is real and persistent. Industrial long-liners and squid jiggers operating in the wider Eastern Tropical Pacific have an incentive to fish the productive water around an aggregation site, and a remote no-take reserve is a tempting target precisely because it is hard to police. Colombian authorities have intercepted and prosecuted incursions over the years, and the combination of the no-take rule, the World Heritage status, and the IMO ATBA gives prosecutors several overlapping legal hooks. Vessel-tracking tools, including satellite AIS and, for some fleets, vessel monitoring systems, feed the enforcement picture, although non-cooperative operators disabling or spoofing transponders remain a problem common to remote reserves.
The enforcement model has a structural limit that Malpelo shares with Galapagos: the coastal state, not the flag state, does the intercepting, and the most consequential offenders are foreign-flag fishing vessels operating at or beyond the boundary. The ATBA and the sanctuary give Colombia a basis to act inside its jurisdiction, but the high-seas fishery beyond the Colombian zone is governed by regional fisheries management bodies and bilateral diplomacy, not by the PSSA.
The fishery pressure has a regional shape. The Eastern Tropical Pacific carries one of the world’s largest distant-water fishing footprints, dominated by industrial squid jiggers and tuna fleets that work the high-seas water surrounding the protected zones of Colombia, Ecuador, Costa Rica and Panama. Sharks are taken both as a target, for the fin trade, and as bycatch on tuna and squid gear, and an aggregation site like Malpelo concentrates the very species the fleets most readily catch. The Colombian response runs on three tracks: physical interception and prosecution inside the zone, vessel-tracking surveillance to build a case against incursions, and engagement through CMAR and the regional fisheries bodies to push fleet discipline on the high seas where the PSSA has no reach. The PSSA is one instrument in that wider effort rather than a standalone solution, and its contribution is to give the charted, internationally recognized boundary that makes interception defensible and that signals to every flag state that the water inside the box is off limits.
A realistic appraisal is that the Malpelo regime has held the line on the worst of the merchant-traffic risk, which was always small, while the fishing-incursion risk remains a live management problem that the PSSA mitigates but does not eliminate. The combination of a charted ATBA, a no-take sanctuary, World Heritage status, a naval garrison, and regional cooperation is stronger than any one of those instruments alone, and it is the layering rather than any single measure that keeps Malpelo’s aggregations intact.
The Eastern Tropical Pacific Marine Corridor
Malpelo does not stand alone. It is one of the flagship sites of the Eastern Tropical Pacific Marine Corridor (CMAR, Corredor Marino del Pacifico Este Tropical), a regional cooperation initiative established in 2004 by the governments of Colombia, Costa Rica, Panama and Ecuador to coordinate management of their flagship Pacific marine protected areas. The corridor links the Malpelo Fauna and Flora Sanctuary (Colombia), the Gorgona National Park (Colombia), the Cocos Island National Park (Costa Rica), the Coiba National Park (Panama), and the Galapagos Marine Reserve (Ecuador). UNESCO and Conservation International supported the corridor concept as a biological corridor connecting the region’s main island sites.
The corridor exists because the animals move. Scalloped hammerheads, silky sharks, whale sharks, sea turtles, and tunas migrate between Malpelo, Cocos, and the Galapagos along predictable routes, and satellite-tagging programs have tracked individual sharks making the crossing. Protecting one node while leaving the connecting water unmanaged protects the animal only part of its life. CMAR is the institutional answer: a framework for joint patrols, shared tracking data, harmonized research, and a common diplomatic front toward the distant-water fishing fleets that exploit the high-seas water between the reserves.
CMAR interacts with the Malpelo PSSA in the same way it interacts with the Galapagos PSSA. It supplies regional intelligence on fleet movements before vessels reach the Colombian zone, it enables occasional combined naval operations along the Malpelo-Cocos and Malpelo-Galapagos corridors, and it provides the platform for joint engagement on the high-seas fishery. The 2017 Colombian expansion of protection around Malpelo, the Yurupari-Malpelo integrated management district, was developed within the corridor’s logic of scaling protection up to the migratory range, even though the formal designation was made under Colombian domestic law rather than through CMAR or IMO.
The 2017 Yurupari-Malpelo expansion
The protection around Malpelo grew sharply in 2017. Colombia declared the Yurupari-Malpelo National Integrated Management District (Distrito Nacional de Manejo Integrado Yurupari-Malpelo) and expanded the protected area well beyond the original sanctuary perimeter. These figures belong to Colombian domestic protected-area designations and are distinct from the 857,150-hectare UNESCO World Heritage marine property: the sanctuary itself was enlarged to a multi-million-hectare extent, and the integrated management district added a further band of regulated-use water, so that the combined area under some form of Colombian protection ran into the millions of hectares. The expansion was part of a wider Colombian push that pushed national coastal-marine protection past the 13 percent mark and met the country’s regional conservation targets.
The integrated management district is a different legal animal from the no-take sanctuary. The sanctuary core remains a strict no-take reserve; the surrounding management district is a managed-use zone where sustainable fishing and resource use are permitted under controls, jointly administered by Parques Nacionales Naturales, the Colombian Navy, and the national aquaculture and fisheries authority. The zonation follows the standard conservation logic of a strictly protected core inside a wider buffer of regulated use, and it reflects the migratory reality that Malpelo’s sharks range far beyond the original sanctuary box.
For a practitioner the expansion matters because it multiplies the boundaries in play. The IMO area-to-be-avoided under Resolution MEPC.97(47) was not enlarged by the 2017 declaration; the ATBA is still the compact rectangle around the island fixed in 2002. The UNESCO World Heritage property still tracks the original sanctuary footprint of about 857,150 hectares. The 2017 figures describe Colombian domestic protected areas that sit outside both. Confusing the 2017 multi-million-hectare district with the 2002 ATBA is the single most common error in describing the Malpelo regime, and it leads to overstating what the IMO measure actually covers.
Scientific monitoring and the connectivity record
Malpelo’s PSSA case rested in part on its scientific value, and the record since designation has reinforced it. The island has become a reference site for shark behavior and for the study of pelagic connectivity across the Eastern Tropical Pacific. Satellite-tagging and acoustic-tagging programs run by Colombian researchers and the Malpelo Foundation, in cooperation with partners at the corridor’s other nodes, have tracked individual scalloped hammerheads and silky sharks making the long crossings between Malpelo, Cocos and the Galapagos, turning the corridor from a conservation hypothesis into a documented migratory network.
The deep-water observations carry their own weight. Malpelo is one of the very few sites where the short-nosed ragged-tooth shark has been filmed in its natural habitat on the deep walls, and the steep bathymetry that makes the island a poor place to live makes it a good place to study a deep, current-swept ecosystem within reach of divers and submersibles. The monitoring time series also tracks the health of the aggregations themselves: counts of schooling hammerheads, the seasonal presence of whale sharks, and the status of the resident Galapagos sharks feed back into the World Heritage reporting that Colombia files under the 1972 Convention.
The monitoring is constrained by the same distance that constrains enforcement. Research presence at Malpelo means multi-day vessel commitments from the mainland, and continuous in-water observation is impossible, so the scientific picture is built from periodic expeditions, fixed tracking receivers, and the data that tagged animals carry to other corridor sites. The result is a coarser but still informative record than a coastal reserve could generate, and it is enough to sustain the case that Malpelo functions as a reservoir and a connectivity hub rather than as an isolated curiosity.
Commercial-shipping context: a feature off the lanes
The Malpelo PSSA imposes almost no cost on merchant shipping, which sets it apart from the PSSAs that wrap busy lanes. The island lies off the main great-circle tracks. Traffic between the Panama Canal and the major South Pacific and South American ports does not need to pass within the ATBA box, and the compact size of the area means that even a ship routing close to Malpelo can clear it with a minor adjustment rather than a planned diversion. There is no port at Malpelo, no bunkering, and no resident trade, so the area-to-be-avoided does not interrupt any supply chain.
That light footprint is why the designation was uncontested and why the chart-correction burden on commercial operators was small. The practical compliance task for a merchant master is to carry the corrected chart showing the ATBA, keep clear of the box, and observe the ordinary MARPOL Convention discharge rules in the surrounding water. For the great majority of ships transiting the Eastern Tropical Pacific, the Malpelo PSSA is a charted feature to stay clear of rather than a routeing constraint that shapes the voyage, which is the appropriate weight for a single remote point feature whose real threat comes from fishing fleets rather than from passing tonnage.
Place in the global PSSA list
Malpelo sits inside a global list of around eighteen IMO-designated PSSAs as of 2026, and its position in that list is instructive. Chronologically it falls between Sabana-Camaguey (Cuba, 1997) and the cluster of mid-2000s designations: the Wadden Sea (2002), the Florida Keys (2002), the Canary Islands (2005), the Galapagos (2005), the Baltic Sea (2005), the Tubbataha Reefs (2006) and Papahanaumokuakea (2007). It is the first Colombian PSSA and one of the earliest applied to a remote oceanic aggregation site rather than to a coastal reef or shelf.
By type, Malpelo belongs with the single-feature, single-APM PSSAs that protect a discrete point of pelagic value with one area-to-be-avoided, in contrast with the multi-measure regimes of the Great Barrier Reef or the Galapagos. Among its peers it is closest in spirit to the later Tubbataha Reefs PSSA, which likewise protects a small, remote, no-take reserve far from the mainland through an IMO measure backed by domestic enforcement. For the full history of the framework from Assembly Resolution A.720(17) through the current Revised Guidelines in A.982(24), and the complete designated list, the PSSA overview is the parent reference.
Relationship to the Galapagos PSSA
The Malpelo and Galapagos PSSAs are the two anchor designations of the Eastern Tropical Pacific, and reading them together clarifies both. They share the regional context: both sit in the same current system, both protect shark and pelagic aggregations, both are UNESCO World Heritage sites, both are CMAR corridor nodes, and both use an area-to-be-avoided with a 500 GT threshold as a core protective measure. A scalloped hammerhead tagged at Malpelo may be photographed months later in the Galapagos, which is the ecological justification for managing them as a pair.
They differ in scale and in the threat they answer. The Galapagos PSSA, designated by Resolution MEPC.135(53) in 2005, wraps an inhabited archipelago of around 30,000 residents with a 60-nautical-mile buffer, an inner ATBA at the marine-reserve boundary, a deep-water route, and a hazardous-cargo prohibition, because it must manage real merchant transit between the Panama Canal and the South Pacific as well as a resident bunker-supply chain. Malpelo, designated three years earlier by Resolution MEPC.97(47), wraps a single uninhabited rock with one compact ATBA, because its threat is illegal fishing rather than merchant pollution. Galapagos is a multi-measure regime over a large inhabited area; Malpelo is a single-measure regime over a small uninhabited one.
The chronology is worth keeping straight: Malpelo (2002) preceded Galapagos (2005). Colombia’s earlier designation helped establish the Eastern Tropical Pacific as a region where the PSSA tool could be applied to remote oceanic aggregation sites, and Ecuador’s later, larger Galapagos designation built on that precedent with a far more elaborate set of measures suited to an inhabited and trafficked archipelago.
Legal mechanism: PSSA status, SOLAS routeing, and UNCLOS limits
The legal force of the Malpelo PSSA comes in layers, and separating them is essential to understanding what the designation can and cannot do. The PSSA designation itself, in Resolution MEPC.97(47), is a recognition: it identifies the area as particularly sensitive and justifies protective measures, but it does not by itself create a no-go zone. The operative restriction is the area-to-be-avoided, which is a routeing measure under SOLAS Chapter V Regulation 10. That is the instrument that reaches foreign-flag ships, because Regulation 10 is part of a convention that flag states have accepted.
Above that sits the framework of the United Nations Convention on the Law of the Sea (UNCLOS). UNCLOS distributes the right to regulate foreign ships between coastal states and flag states. In the territorial sea a coastal state has broad authority; in the exclusive economic zone its authority over vessel-source pollution is constrained to generally accepted international rules, the formula of Article 211(5), with additional measures in clearly defined areas only where IMO-backed conditions are met. The IMO designation and the SOLAS routeing measure supply exactly the international acceptability that UNCLOS requires for a coastal-state measure to bind foreign ships. This is why the ATBA had to be adopted through the IMO machinery and not simply proclaimed by Colombia.
The recommendatory character of an area-to-be-avoided is the practical limit. Regulation 10 measures are framed as “should,” not “shall,” which reflects the UNCLOS reservation that a flag state retains primary jurisdiction over its ships on the high seas and the freedom of navigation that survives in the EEZ. Colombia’s stronger lever inside the sanctuary is its domestic no-take law and its sovereign-rights jurisdiction, which let it act against a vessel that is fishing or that has entered the protected water, independent of whether the ATBA alone would have been enough. The two instruments together, the IMO routeing measure for international recognition and Colombian law for enforcement reach, are what make the regime work.
Limitations and practitioner notes
The Malpelo PSSA is narrow by design, and a practitioner should treat it as one charted feature rather than a broad regulatory zone. A few caveats matter in route planning and compliance.
First, the PSSA designation is not itself a prohibition. The enforceable element is the area-to-be-avoided under SOLAS V Regulation 10, and an ATBA is recommendatory: it says ships “should” avoid the area. A master who enters the box has not automatically breached a binding IMO rule the way a master crossing a wrong-way traffic lane has, but the master has entered a Colombian no-take sanctuary and World Heritage water and exposed the ship to Colombian enforcement. Treat the ATBA as a hard boundary in practice even though its IMO status is advisory.
Second, the measure does not regulate discharges. The Eastern Tropical Pacific is not a MARPOL Annex I Special Area, so inside the Malpelo PSSA the general convention discharge standards apply, not Special-Area limits. A common error is to assume PSSA status automatically tightens the oil or garbage discharge regime; at Malpelo it does not. The ordinary MARPOL Annex I Regulation 15 oil-discharge criteria, the Annex V garbage rules, and the Annex IV sewage rules govern, subject to the prudence any operator should exercise near a sensitive site.
Third, the threshold catches fishing vessels of all sizes. Unlike most ATBAs, which apply only above a tonnage floor, the Malpelo measure names fishing vessels expressly and without a size limit, alongside ships above 500 GT. An operator of a small fishing vessel cannot rely on being below a gross-tonnage threshold to claim the ATBA does not apply.
Fourth, enforcement is single-jurisdictional and resource-limited. The Colombian Navy intercepts; the flag state of an offending fishing vessel often does not cooperate; and the distance from the mainland means coverage is intermittent. Detainable-item exposure for a compliant merchant ship is low because such ships have no reason to enter, but the real-world enforcement record is dominated by illegal fishing rather than by merchant routeing breaches, and the regime’s effectiveness against that threat depends on patrol assets and tracking data, not on the chart symbol alone.
Fifth, the boundaries can be confused. The IMO ATBA box, the Colombian sanctuary, and the later Yurupari-Malpelo management district are three perimeters of different sizes. The ATBA is the compact rectangle around the island; the sanctuary and the World Heritage property share a larger boundary of about 857,150 hectares; the integrated management district is larger still. Cite the right boundary for the right purpose, and do not treat the ATBA coordinates as the limit of the protected water.
See also
- Particularly Sensitive Sea Area framework overview
- Particularly Sensitive Sea Area: Galapagos Archipelago
- Particularly Sensitive Sea Area: Sabana-Camaguey
- Particularly Sensitive Sea Area: Great Barrier Reef
- Particularly Sensitive Sea Area: Tubbataha Reefs
- Particularly Sensitive Sea Area: Wadden Sea
- Particularly Sensitive Sea Area: Baltic Sea
- Particularly Sensitive Sea Area: Papahanaumokuakea
- SOLAS Chapter V Safety of Navigation
- UNCLOS overview for shipping
- MARPOL Convention
- MARPOL Annex I oil pollution prevention
- Calculator catalogue