The Paracas National Reserve Particularly Sensitive Sea Area is the PSSA designated by the International Maritime Organization through Resolution MEPC.106(49), adopted on 18 July 2003 at the forty-ninth session of the Marine Environment Protection Committee, covering the 217,594-hectare sea area of the Paracas National Reserve off Pisco Province in the Department of Ica, Peru. It was the first PSSA proposed by Peru and the first on the South American Pacific coast, following the Malpelo PSSA of Colombia by sixteen months and preceding the Galapagos PSSA of Ecuador by two years. The reserve is Peru’s only marine protected area, created by Supreme Decree No. 1281-75-AG of 25 September 1975, and the sea inside it is fed by the Humboldt Current upwelling that makes the Peruvian coast one of the most productive in the world. The Peruvian proposal sought two protective measures: a prohibition on tanker navigation within the reserve sea area and a prohibition on any discharge from ships inside it, supported by a traffic separation scheme in the approaches to Puerto de Pisco and an area to be avoided processed as a routeing measure under SOLAS Chapter V Regulation 10. The designation was assessed under the PSSA Guidelines then in force, Assembly Resolution A.927(22), against ecological, socio-economic and scientific criteria documented in the Peruvian submission. The reserve holds large guano-bird colonies, three of the largest South American fur seal colonies on the Peruvian coast, sea lions, and one of the three largest Humboldt penguin colonies on the coast, alongside the entire Peruvian population of the Peruvian diving petrel. For the global framework see the PSSA overview, and for the regional pair read the Galapagos and Malpelo designations.
Background: the PSSA framework and Paracas in the list
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 instrument in force today is Assembly Resolution A.982(24) of 1 December 2005, the Revised Guidelines, as later amended by Resolution MEPC.267(68) of 15 May 2015. Paracas predates both. It was assessed under the earlier Assembly Resolution A.927(22) of 29 November 2001, the Guidelines that the Marine Environment Protection Committee applied when it considered the Peruvian submission in 2003. The resolution text itself cites A.927(22) as the procedural basis, which is the same generation of guidelines used for the Malpelo designation a year earlier.
Paracas holds a specific place in the chronology. It was designated by Resolution MEPC.106(49) on 18 July 2003, after the Great Barrier Reef (1990), the Sabana-Camaguey (Cuba, 1997), the Malpelo (Colombia, March 2002), the Wadden Sea and the Florida Keys (both 2002), and before the Western European Waters (2004), the Galapagos and the Baltic Sea (both 2005). It was the first PSSA on the South American mainland and the first to protect a Humboldt Current upwelling system rather than a tropical reef or an oceanic aggregation site.
The Paracas case sits between the two emphases that run through the PSSA list. Most PSSAs answer either a pollution and collision threat from merchant transit (the Great Barrier Reef, the Wadden Sea) or an illegal-fishing threat at a remote reserve (the Malpelo box). Paracas answers a tanker threat tied to a working oil terminal. The reserve hosts a port terminal for large ships and a multi-buoy offshore terminal that supplies oil from tankers to a regional refinery, and the Peruvian proposal named the transport and transhipment of oil, sulphuric acid and other noxious substances by tankers as the major source of environmental risk. The protective measures follow from that diagnosis: keep tankers out of the reserve water and keep their discharges out of it.
Geography: the Paracas Peninsula and Bahia de la Independencia
The Paracas National Reserve lies on the south-central coast of Peru, in Pisco Province in the Department of Ica, about 250 km south of Lima. The designated sea and coastal area is defined in the resolution by seven geographic points and is reproduced on Peruvian navigation chart HIDRONAV-2170, “Coast of Peru: Pisco-Paracas-Bahia Independencia.” The northernmost corner sits at about 13 degrees 46.9 minutes South and the southernmost at about 14 degrees 26.7 minutes South, so the reserve spans roughly 40 minutes of latitude, close to 40 nautical miles of coast, with an offshore reach out to about 76 degrees 30 minutes West.
The coastline is varied. It runs from the shallow Bay of Paracas in the north, past the Paracas Peninsula and Punta Carreta, to the deep indentation of Bahia de la Independencia in the south, with Morro Quemado and Punta Gallinazo on its southern flank. The Bay of Paracas is shallow, between 0 and 7 meters over much of its area and deeper only near Punta Pejerrey, which is part of why a grounding or a spill in that water would be hard to disperse. The reserve includes several islands, the main ones being Isla San Gallan, the Ballestas Islands (Islas Ballestas) and the Independencia island group, the rock platforms that carry the guano-bird and seal colonies.
The land is desert. The Paracas coastal desert runs on high temperatures and very low rainfall, with average annual precipitation measured in fractions of a millimeter, and the prevailing south and south-west winds reach an average of about 14.9 km/h, gusting in the strong shore wind locally called the “Paraca” to about 32 km/h. The combination of an arid, almost rainless shore and a cold, nutrient-rich sea is the signature of the Humboldt system, and it is what concentrates so much marine life against such a barren coast.
The Humboldt Current and why Paracas is so productive
The thing that makes Paracas worth protecting is not the rock but the water column, and the water column is a product of the Humboldt Current upwelling. The Peruvian Sea is one of the world’s richest in hydrobiological resources because of the coastal upwelling driven by the trade winds and the South Pacific anticyclone. The trade winds push the surface water of the Peruvian coast from south-east to north-west; the rotation of the Earth and the shape of the coast bend that flow away from the shore; and the void it leaves is filled by cold, nutrient-rich water rising from deeper layers. This is the Peruvian upwelling system, and the sea off Paracas sits in one of its most productive cells.
The biology follows the nutrients. The upwelled water carries the inorganic nutrients that feed a phytoplankton bloom; the bloom feeds the small pelagic fish, principally anchovy (Engraulis ringens), sardine, mackerel and silverside; and those in turn feed the seabirds, the seals and the larger predators. The resolution records the area as one of the most productive on the coast, with the cold Peruvian Current and submarine counter-currents driving the upwelling that “starts the trophic chain which makes the sea of Paracas one of the richest in the world.” Despite its tropical latitude near 14 degrees South, the most striking feature of the Peruvian Sea here is its cold water, the surface expression of that vertical nutrient pump.
The diversity is documented. The Peruvian protected-areas authority recorded 1,543 species across the reserve in a January 2000 inventory: 317 algae, 194 molluscs, 286 marine arthropods, 168 fish, 216 birds and 36 mammals, among others. The marine flora alone runs to 254 recorded species of algae. That richness, concentrated against a near-rainless desert, is the ecological criterion that carried the PSSA case, and it is the asset that a tanker spill in the shallow, slow-flushing reserve water would put at risk.
Guano birds, seals, sea lions and the Humboldt penguin
The fauna is the public face of the reserve. The bird life recorded in the Peruvian submission includes condors, guanay cormorants, boobies, pelicans, flamingos, terns, gulls and a long roll of migratory shorebirds that arrive from Alaska, British Columbia, Alberta and Saskatchewan, making Paracas a key stopover on the Pacific flyway. The reserve has been recognized as a Regional Reserve for Migratory Birds by the Western Hemisphere Shorebird Reserve Network (WHSRN) since 28 September 1991, and the migratory shorebirds depend on the intertidal feeding grounds of the Bay of Paracas wetland and the Rio Pisco estuary, which the resolution flags as highly vulnerable to anthropogenic change.
The seals and sea lions are concentrated on the islands and headlands. The reserve holds three of the largest stable colonies of South American fur seal (Arctocephalus australis) on the Peruvian coast, alongside the sea lion (Otaria byronia), on rock platforms at Morro Quemado, Islas Independencia, Santa Rosa, Mendieta, Isla Zarate, Punta Arquillo, Punta Lechuza, Punta Lagarto, Isla San Gallan, the Ballestas and the Chincha islands. The colonies recovered after the reserve put an end to the indiscriminate hunting that had driven them down: the total seal population across all colonies was about 2,048 in 1976 and about 15,821 by 1982, and the populations are no longer considered endangered.
Two species mark the conservation stakes most sharply. The Humboldt penguin (Spheniscus humboldti) is in danger of extinction, and one of the three largest colonies on the Peruvian coast is found at Bahia de la Independencia. The Peruvian diving petrel is even more concentrated: the entire Peruvian population of the species is confined to the sea area of the Paracas National Reserve. A single oil event in the wrong place could touch a substantial share of a national population, which is the kind of concentrated vulnerability the PSSA tool is built to answer. The marine otter (Lutra felina), the Humboldt penguin and the Chilean flamingo (Phoenicopterus chilensis) were already listed as endangered under Peruvian Ministerial Resolution No. 1082-90-AG of 1990 before the IMO designation.
Resolution MEPC.106(49): the designation
The Peruvian submission was considered by the Marine Environment Protection Committee and adopted at MEPC 49 as Resolution MEPC.106(49) on 18 July 2003, designating the Paracas National Reserve as a Particularly Sensitive Sea Area. The resolution recites the ecological, social, cultural and educational value of the reserve and its vulnerability to damage by international shipping traffic, notes that the Guidelines under Resolution A.927(22) set out the designation procedure, and records that the Committee agreed the A.927(22) criteria were fulfilled. The operative paragraph designates the Paracas National Reserve “as defined in the Annex to this resolution” as a Particularly Sensitive Sea Area.
The resolution is explicit about the dual-track IMO architecture. The preamble notes that the forty-ninth session of the NAV Sub-Committee considered an Area to be Avoided (ATBA) and agreed to its establishment, and a later paragraph of the annex records that the Maritime Safety Committee, at its seventy-fifth session in May 2002, approved Peru’s proposal to establish maritime traffic separation schemes for four ports, including Puerto de Pisco, which is located in an area adjacent to the reserve. The split is the standard one: a PSSA whose protection relies on routeing needs the routeing measure adopted under SOLAS Chapter V Regulation 10 through the navigation sub-committee and the Maritime Safety Committee, while the PSSA designation itself is adopted by MEPC under the environmental track. The MEPC resolution supplies the ecological recognition; the SOLAS routeing measures supply the legal reach over foreign-flag ships.
The reserve’s national pedigree predates the IMO process by decades. It was created as Peru’s only marine reserve by Supreme Decree No. 1281-75-AG of 25 September 1975 and includes within its boundaries the Paracas National Prehistoric Park designated by Supreme Decree No. 15 of 21 June 1960. San Gallan island and the Ballestas islands were incorporated by a Ministry of Tourism resolution of 5 September 1996, together with two miles of surrounding sea measured from the coastline. The Peruvian Maritime Authority had already issued a national regulation, Departmental Resolution No. 0103-96-DCG of 17 April 1996, prohibiting the passage of ships carrying hydrocarbons and other polluting substances in the reserve sea area, so the IMO designation internationalized a restriction Peru had already imposed domestically.
The protective measures: tanker exclusion, no discharge, Pisco TSS
The Peruvian proposal set out two measures it asked IMO to recognize. The first measure is a prohibition on the navigation of tankers within the sea area of the Paracas National Reserve, as defined on the shipping charts. The intent is plain: a laden or a ballast tanker has no need to enter the reserve water on a voyage to another port, and keeping tankers outside the boundary removes the dominant spill vector at source. The resolution notes that the prohibition will not cause harm or financial loss to tanker owners, since they do not need to pass through the reserve en route to other ports and so waste no time avoiding it.
The second measure is a prohibition on any kind of discharge from ships inside the reserve sea area, including sewage and waste. This is broader than the general MARPOL Convention discharge regime, which permits controlled overboard discharge of treated effluent, oily water below the Annex I Regulation 15 oil-discharge criteria, comminuted Annex IV sewage at distance from land, and food wastes under Annex V. Inside the reserve the proposal seeks zero discharge, which catches the bilge water, sewage and waste streams that the resolution identifies as risks to the ecological health of the reserve.
The routeing element that carries the legal weight over foreign-flag ships is the traffic separation scheme for the approaches to Puerto de Pisco, approved by the Maritime Safety Committee at its seventy-fifth session in May 2002, together with the area to be avoided that the NAV Sub-Committee considered and agreed at its forty-ninth session. A traffic separation scheme organizes opposing streams of traffic into lanes to reduce collision risk in the approaches to the port adjacent to the reserve, and an area to be avoided is a charted box that ships should keep clear of. Both are routeing measures under SOLAS Chapter V Regulation 10, reproduced in the IMO Ships’ Routeing publication and on the navigation charts. The package matters because the principal port activity at Paracas is the arrival, stay and departure of tankers at Puerto General San Martin and at the offshore multi-buoy terminal that loads and unloads hydrocarbons and sulphuric acid.
Why a tanker exclusion rather than a discharge Special Area
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, recommended routes, and, where a parallel MARPOL Special Area applies, discharge restrictions. Peru built its case around traffic measures and a tanker exclusion rather than a discharge designation, and the choice tracks the threat and the legal options.
The waters off Peru are not a MARPOL Annex I oil Special Area, so the PSSA could not borrow Annex I Special-Area discharge limits the way a Mediterranean or Baltic PSSA can. What the reserve faced was a concrete tanker risk: a working oil terminal, a multi-buoy offshore mooring handling hydrocarbons and sulphuric acid, and an average of 395 to 535 merchant ships a month passing in the vicinity or through the reserve water. The transport and transhipment of oil and noxious substances by tankers, with the quantities involved, was named the major source of environmental risk, above all because of spill, toxicity and flammability. A tanker exclusion plus a Pisco traffic separation scheme attacks that vector directly, while the discharge prohibition closes the operational-discharge gap that a non-Special-Area would otherwise leave open.
The proposal recorded that no shipping accident, grounding, collision or spill had occurred in the reserve to that date, but argued that an operational or accidental spill could occur at any time, and that privatization of the state port enterprises was expected to increase the movement of these products as the economy grew. The PSSA was a preventive measure taken before a casualty rather than a reaction to one, which distinguishes the Paracas case from the Galapagos designation that followed the 2001 Jessica spill.
The international recognition layer
Paracas reached IMO carrying a stack of prior international recognitions, and the PSSA designation added the shipping-specific layer to them. The reserve has been on the List of Wetlands of International Importance of the Ramsar Convention since 30 March 1992, listed not as a single wetland but as a series of wetlands, principally the Bay of Paracas wetland and the Rio Pisco estuary that the migratory shorebirds depend on. It has been a WHSRN Regional Reserve for Migratory Birds since 28 September 1991. At the time of designation a proposal was being prepared to submit the reserve to UNESCO for declaration as a Biosphere Reserve.
These instruments operate alongside the IMO PSSA without substituting for one another. The Ramsar listing and the WHSRN recognition codify the wetland and migratory-bird value internationally; the Peruvian national-reserve status under the 1975 Supreme Decree supplies the domestic protected-area law; and the PSSA supplies the IMO measures that reach foreign-flag shipping through SOLAS routeing. The PSSA proposal cited the Ramsar and WHSRN recognitions and the endangered-species listings as evidence of the recognized value that the PSSA Guidelines require, which is the same evidentiary pattern the Malpelo and Galapagos proposals used with their UNESCO World Heritage status.
Enforcement and the Peruvian Maritime Authority
The protective measures are only as good as the enforcement behind them, and at Paracas that enforcement runs on Peruvian institutions. The reserve is administered by the national protected-areas authority, with the marine and navigational dimension under the Peruvian Maritime Authority (the Direccion General de Capitanias y Guardacostas, DICAPI, of the Peruvian Navy). The Maritime Authority issued the 1996 Departmental Resolution that first prohibited hydrocarbon-carrying ships from the reserve water, and it administers the pilotage, anchorage and patrol regime in the Pisco approaches and the reserve. The Hydrographic and Navigation Department of the Peruvian Navy, which produces the HIDRONAV charts that depict the PSSA and its routeing measures, also conducts the marine research cited in the submission.
The reserve sits in a working industrial coast. The Pisco-Paracas area carries a port terminal for large ships handling fish meal, salt and sulphuric acid, the multi-buoy oil terminal supplying the regional refinery, and the industrial and artisanal fishing fleet that the upwelling sustains, including barges and wharves for direct unloading of hydrobiological products. The enforcement task is therefore not to keep an empty sea empty, as at Malpelo, but to manage a busy port-adjacent water so that the tanker traffic uses the traffic separation scheme and the approaches to Puerto General San Martin and stays out of the reserve interior, while the fishing and tourist traffic operates under the national-reserve rules. Over 120,000 visitors a year reach the reserve, and the tourist boats running to the Ballestas Islands add a further traffic stream to manage.
Commercial-shipping context: a coastal exclusion, not a great-circle diversion
The commercial impact of the Paracas PSSA on through-traffic is modest, because the reserve hugs the coast rather than straddling an offshore lane. Merchant ships transiting the Peruvian coast between, for example, Callao to the north and the southern Peruvian and Chilean ports run offshore of the reserve boundary, and the tanker prohibition removes a route option that a tanker bound for another port had no reason to use. The resolution makes the point directly: tankers do not need to pass through the reserve en route to other ports, so the prohibition costs them no time and no money.
The traffic that the measures actually shape is the local approach traffic. Tankers calling at the Pisco oil terminal, bulk ships loading fish meal and salt at Puerto General San Martin, and the ships calling at the multi-buoy mooring all use the Pisco approaches, and the traffic separation scheme organizes that traffic into lanes and keeps it clear of the reserve interior. For a merchant master the compliance task is to carry the corrected HIDRONAV chart showing the PSSA, the traffic separation scheme and the area to be avoided, to follow the scheme in the Pisco approaches, to keep any tanker out of the reserve water, and to make no discharge inside the boundary. For ships not calling at Pisco the PSSA is a charted coastal feature to keep clear of rather than a routeing constraint that reshapes the voyage.
Relationship to the Galapagos and Malpelo PSSAs
Paracas is the third anchor of the eastern Pacific PSSA cluster, with Galapagos and Malpelo, and reading the three together clarifies each. The shared regional context is the eastern Pacific marine environment and the dependence of seabirds, marine mammals and fisheries on cold, productive water. The chronology runs Malpelo (March 2002), Paracas (July 2003), then Galapagos (July 2005), so Paracas is the middle designation and the first on the South American mainland.
The differences are more instructive than the similarities. Paracas sits in the cold Humboldt Current upwelling against the desert coast of mainland Peru, while Galapagos and Malpelo sit in the warmer Eastern Tropical Pacific around oceanic islands far offshore. The threat profiles differ accordingly. Malpelo answers illegal fishing at a remote uninhabited rock with a single compact area to be avoided; Galapagos answers merchant transit between the Panama Canal and the South Pacific plus a resident bunker-supply chain with a 60-nautical-mile buffer, an inner area to be avoided, a deep-water route and a hazardous-cargo prohibition; Paracas answers tanker risk at a working coastal oil terminal with a tanker exclusion, a no-discharge rule and a port traffic separation scheme. Galapagos is a multi-measure regime over an inhabited archipelago, Malpelo a single-measure regime over an uninhabited rock, and Paracas a coastal regime built around a port and its tanker trade.
One point of confusion is worth heading off. The eastern Pacific gained renewed PSSA attention when two further areas off Peru were agreed in principle at MEPC 83 in April 2025, pending submission of their associated protective measures, as the PSSA overview records. Those are separate, newer proposals and should not be conflated with the long-established Paracas designation of 2003. Paracas has been a designated PSSA under MEPC.106(49) for over two decades; the 2025 items are at an earlier stage of the same process.
The vulnerability case the proposal had to prove
The PSSA Guidelines require a proposing state to show not just that an area is valuable but that it is vulnerable to damage from international shipping, and the Peruvian submission built that vulnerability case on the physical character of the reserve as much as on the traffic. The Bay of Paracas is shallow, 0 to 7 meters over much of its area, which means a spill there would sit in a confined, slowly flushed basin rather than dispersing into open water. The Rio Pisco delivers a variable but constant inflow of fresh water into the bay, especially in summer, lowering salinity and producing the brackish intertidal feeding ground that the migratory shorebirds rely on, so an oil film over that intertidal zone would strike exactly the micro-topography that feeds the birds.
The reserve also has a low capacity to absorb damage. The submission describes it as a highly sensitive ecosystem with limited capacity to absorb adverse environmental effects, and it identifies four discrete risk streams from ships: accidental or operational spills of oil and sulphuric acid from tankers and the multi-buoy terminal; the pumping of bilge water; the discharge of sewage and waste; and the increased chance of collision or grounding as traffic grows. The currents add a further factor. The system off the Peruvian coast runs northward, so a release inside or just south of the reserve would tend to be carried along the reserve coast rather than away from it, concentrating the exposure on the very colonies the designation protects.
The traffic figures gave the case its weight. The submission recorded an average of 395 to 535 merchant ships a month passing in the vicinity of the reserve or through it, and the port-call series for Pisco showed traffic rising from 84 ships in 1990 to 186 in 1999, more than doubling over the decade. With privatization of the state port enterprises expected to push the movement of oil and noxious products higher, the proposal argued that the absence of a past casualty was not evidence of safety but a window to act before one occurred. That preventive logic, a documented value plus a documented and rising risk plus a confined, slow-flushing receiving environment, is what carried the A.927(22) criteria for Paracas.
The Paracas culture, archaeology and the socio-economic criterion
The PSSA case rested on more than ecology. The socio-economic and scientific criterion families of the Guidelines were satisfied by the reserve’s tourism economy, its fisheries, and its archaeological heritage, all of which a marine pollution event would put at risk. Tourism is substantial and growing: the submission recorded over 120,000 visitors a year and a flow that rose from 121,323 in the 1976 to 1980 period to 412,211 in the 1994 to 1999 period, drawn by the wildlife of the Ballestas Islands, the desert scenery, and the archaeology. The tourist boats running to the Ballestas to see the guano birds and the seals are themselves a managed traffic stream inside the reserve.
The archaeology is exceptional. The Paracas region holds around 104 archaeological sites, most of them within the reserve, covering every period of pre-Hispanic Andean society, and the reserve includes the Paracas National Prehistoric Park designated by Supreme Decree No. 15 of 21 June 1960. The Paracas culture that gives the reserve its name left dwelling mounds, shell middens, pottery, weaving and burial sites along the coast, some dating to between 1000 and 800 BC at sites such as Atenas Beach and the Paracas Cave era mounds. The reserve also carries the El Candelabro geoglyph, a large prehistoric geoglyph cut into a coastal slope on the peninsula, and the Julio C. Tello Site Museum and interpretation center. This cultural inventory tied the conservation case to a tourism economy and a national-heritage interest, which is the socio-economic value the Guidelines ask a proposer to document.
The fisheries supplied the human-economy strand. The principal productive activity in the reserve is fishing, both industrial and small-scale, including fish-farming, with barges and wharves for the direct unloading of hydrobiological products, and the Bahia de la Independencia is the leading place on the Peruvian coast for the production and harvesting of shellfish. The scallop fishery (Argopecten purpuratus) booms after El Nino events and supports a large market and a migrant fishing population that moves into the reserve area during those periods. A spill that closed the shellfish grounds or tainted the catch would hit a working coastal economy, not just a wildlife refuge, and the submission made that linkage explicit in arguing the vulnerability of the area to international maritime activity.
Place in the global PSSA list
Paracas sits inside a global list of around nineteen IMO-designated PSSAs as of 2026, and its place in that list reflects its character. Chronologically it falls in the dense cluster of early-2000s designations between Malpelo (2002) and Galapagos (2005), alongside the Wadden Sea (2002), the Florida Keys (2002) and the Western European Waters (2004). By type it belongs with the coastal PSSAs whose protection is built around port-approach routeing and a discharge or tanker restriction, closer in design to the Canary Islands regime than to the single-box Malpelo model.
What sets Paracas apart in the list is the ecosystem it protects. It is the only PSSA in the Humboldt Current system, one of the most productive upwelling regimes on Earth, and it protects that productivity against a tanker risk tied to a working oil terminal rather than against the reef-grounding or aggregation-poaching threats that dominate the rest of the list. 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.
Legal mechanism: PSSA status, SOLAS routeing, and UNCLOS limits
The legal force of the Paracas PSSA comes in layers, and separating them matters for understanding what the designation can and cannot do. The PSSA designation in Resolution MEPC.106(49) is a recognition: it identifies the reserve sea area as particularly sensitive and justifies protective measures, but it does not by itself create a binding no-go zone for foreign ships. The operative restrictions over foreign-flag shipping are the routeing measures, the Pisco traffic separation scheme and the area to be avoided, which are adopted under SOLAS Chapter V Regulation 10 through the Maritime Safety Committee. Regulation 10 is part of a convention that flag states have accepted, which is what gives those measures reach against ships of other flags.
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 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 limited to generally accepted international rules under Article 211(5), with additional measures in clearly defined areas only where IMO-backed conditions are met. The IMO designation and the SOLAS routeing measures supply the international acceptability that UNCLOS requires for the coastal-state measures to bind foreign ships. This is why the tanker exclusion and the traffic separation scheme had to be processed through IMO and not simply proclaimed by Lima, even though Peru had already imposed a domestic hydrocarbon-carriage prohibition by its 1996 Departmental Resolution.
The character of a traffic separation scheme differs from that of an area to be avoided. A traffic separation scheme adopted by IMO is, for the lanes and separation zones it defines, a measure that ships are required to comply with under COLREG Rule 10 once it is in force in the area; an area to be avoided is framed as a recommendation that ships “should” avoid. Peru’s stronger lever inside the reserve itself is its domestic protected-area law and its territorial-sea and EEZ jurisdiction, which let it act against a tanker that enters the prohibited water independent of the recommendatory status of the area to be avoided. The two together, the IMO routeing measures for international recognition and Peruvian law for enforcement reach, are what make the regime work.
Limitations and practitioner notes
The Paracas PSSA is a coastal, port-adjacent regime, and a practitioner should treat it as a charted exclusion plus a routeing scheme rather than a broad offshore zone. Several caveats matter in route planning and compliance.
First, the PSSA designation is not itself the operative restriction. The enforceable elements for foreign ships are the routeing measures under SOLAS V Regulation 10: the traffic separation scheme in the Pisco approaches, which carries the force of COLREG Rule 10 where it applies, and the area to be avoided, which is recommendatory. A master should treat the reserve boundary and the area to be avoided as a hard limit in practice, because entering the reserve water also exposes the ship to Peruvian protected-area enforcement and to the 1996 domestic hydrocarbon-carriage prohibition, regardless of the advisory IMO status of the area to be avoided.
Second, the measure is not a MARPOL Special Area. The waters off Peru are not a MARPOL Annex I oil Special Area, so outside the reserve boundary the general convention discharge standards apply, not Special-Area limits. Inside the reserve the Peruvian proposal seeks a total prohibition on discharge, which is stricter than the convention defaults, but a common error is to assume PSSA status automatically converts the surrounding sea into a tightened-discharge regime. It does not. The ordinary Annex I Regulation 15 oil-discharge criteria, the Annex IV sewage rules and the Annex V garbage rules govern the approaches, subject to the prudence any operator should exercise near a sensitive site.
Third, the tanker prohibition is targeted, not universal. It bars tanker navigation inside the reserve sea area; it does not bar tankers from calling at the Pisco oil terminal and the multi-buoy mooring, which are the reason tanker traffic exists in the area at all. The compliance line is geographic: use the approaches and the terminal, follow the traffic separation scheme, and stay out of the reserve interior. Confusing the terminal-approach traffic with the reserve-interior prohibition is the most common misreading of the regime.
Fourth, enforcement is single-jurisdictional and concentrated on a busy coast. The Peruvian Maritime Authority and Navy do the intercepting and the patrolling, and the practical risk picture is dominated by the tanker and bulk traffic to Pisco and the fishing fleet rather than by through-traffic. Detainable-item exposure for a compliant transiting ship is low because it has no reason to enter the reserve, but operators calling at Pisco must hold current charts, comply with the traffic separation scheme, and observe the discharge prohibition inside the boundary.
Fifth, the boundaries and the dates can be confused. The IMO PSSA under MEPC.106(49) dates from 18 July 2003 and is assessed under the older A.927(22) Guidelines, not the current A.982(24). The reserve itself dates from the 1975 Supreme Decree, the Ramsar listing from 1992, and the WHSRN recognition from 1991. The two further Peru areas agreed in principle at MEPC 83 in 2025 are separate proposals. Cite the right instrument and date for the right purpose, and do not treat the 2025 items as part of the established Paracas designation.
See also
- Particularly Sensitive Sea Area framework overview
- Particularly Sensitive Sea Area: Galapagos Archipelago
- Particularly Sensitive Sea Area: Malpelo Island
- Particularly Sensitive Sea Area: Sabana-Camaguey
- Particularly Sensitive Sea Area: Great Barrier Reef
- Particularly Sensitive Sea Area: Canary Islands
- Particularly Sensitive Sea Area: Western European Waters
- SOLAS Chapter V Safety of Navigation
- UNCLOS overview for shipping
- MARPOL Convention
- MARPOL Annex I oil pollution prevention
- Calculator catalogue