Protecting Peru's Giant Manta Rays

Expedition Briefing


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The Research

The Giant manta ray (Manta birostris) is an iconic and highly vulnerable species. The world’s largest giant manta population is known to migrate from Ecuador into northern Peruvian waters, and historically has been landed and exposed to unmanaged and unmonitored fisheries. In 2012, research by Planeta Océano (PO) and partners documented the occurrence, bycatch, and intentional harvest of manta rays in northern Peru. Captured individuals included pregnant females, suggesting the discovery of an important reproduction area. Given the low reproductive rate of this species, continued fishing pressure jeopardized its conservation. Based on this research, PO and The Marine Institute of Peru (IMARPE) collaborated with Peruvian authorities and international organizations to achieve national protection for manta rays in 2015. PO has also mapped the occurrence of mantas in northern Peruvian waters since 2014, as well as worked with local fishermen to introduce manta ecotourism as a viable alternative to harvest.

Building upon our efforts to date, this Earthwatch project is now fundamental to enhance understanding regarding the spatial ecology, population structure and behavior of giant manta rays in northern Peru. This is particularly important as manta rays, despite being legally protected, still face threats due to incidental fisheries. Furthermore, there is limited binational and regional collaboration for manta ray conservation, and there is a need to further document connectivity to strengthen international efforts.

Volunteers will have the chance to snorkel alongside these beautiful behemoths as they photograph individual mantas, document markers such as scars, take measurements, and assist scientists in collecting genetic samples. This information will help researchers to learn where and how manta rays migrate in order to better understand the connectivity that may exist between populations.

Research Aims

This project aims to strengthen and guide vital conservation and adaptive management measures for this species. This includes delivering recommendations to:

  1. Help mitigate bycatch interaction in the area.
  2. Help fishermen promote low-impact, community-based tourism development based on manta ray watching.
  3. Promote binational cooperation between Peru and Ecuador based on the connectivity of this population.

By measuring water surface temperatures, sampling zooplankton (a critical manta ray food source), surveying seabirds and marine megafauna such as whale sharks and sea turtles, and collecting genetic samples of giant manta rays, researchers will be able to gain a greater understanding of the environmental factors that impact these natural habitats. Data collected will also help provide a greater understanding of manta rays and will build public awareness and appreciation for marine resources.

This data will provide important ecological baseline information for this region as well as help guide future management actions regarding environmental change. The research will be carried out in collaboration with local artisanal fishermen from the Mantas Pacífico Tropical Association. The Association, founded through efforts of Planeta Océano, is pioneering manta ray ecotourism in Peru and aims to showcase marine conservation as a pathway for sustainable development. Results from this Earthwatch project will help guide manta conservation, plus directly support the Association and the socioeconomic development of its community.

While each Earthwatch team will go out to collect observational data of manta rays, their presence cannot be guaranteed.

Sometimes these gentle giants can be elusive, but that is part of the reason your support in data collection is so important—to understand the patterns of these amazing animals and learn more about what might be driving their distribution.

How You Will Help

Volunteers will assist with the following:

  1. Estimate relative population size, structure, habitat use and seasonality for giant manta rays in northern Peru
  2. Identify potential migratory behavior as well as natural or fishery-induced threats to manta rays
  3. Assess genetic variability among manta rays in northern Peru in relation to manta rays encountered in Ecuador
  4. Assess zooplankton composition and oceanographic variables (sea surface temperature, salinity, pH and Oxygen) in manta ray aggregation sites, along a three year time period

Volunteers will help achieve these objectives with the following research tasks:

  • Conduct on-board observations and snorkel to collect data on sightings of manta rays
  • Once mantas are encountered, volunteers will record surface observations, and when safe to do so, snorkel or free-dive to collect underwater video/photographs of the underside of individuals for photo identification. While underwater, volunteers will also help assess the sex and maturity of individuals, as well as note scars produced from mating, fishing activity, or natural predators
  • Collect data on environmental parameters (e.g. Sea Surface Temperature, pH, etc.)
  • Collect seabird and marine data, such as sightings of whale sharks, humpback whales, dolphins and sea turtles in the area. These species are encountered frequently. This opportunistic data will feed into future investigations for the project
  • Select and organize appropriate photo ID images from material collected at field and analyze any laser-caliper footage taken to measure mantas
  • Consult our manta photo ID database to identify re-sightings and potential migratory behavior of individuals
  • Prepare and organize materials and equipment for field and laboratory research
  • Help set up nets for plankton sampling and conduct plankton hauls
  • Collect, preserve, and label plankton samples
  • Participate in lab work for plankton analysis
  • Collect and preserve genetic samples (mucus) from encountered manta rays.
  • Help extract DNA, prepare materials, and cut tissue in laboratory
  • Input data collected from the field into spreadsheets and databases

This project is strongly supported by our work with the local community, and so volunteers will also be participating in community activities such as visiting local artisans and schools.

Life in the Field

Weather and research needs can lead to changes in the daily schedule. We appreciate your cooperation and understanding.

  • Day 1: Arrival in the late afternoon, tour of accommodations, settle in and rest, dinner, safety briefing and research overview and training.
  • Days 2–6: Data collection, at least two days will be spent searching for manta rays, and one day will be spent carrying out plankton sampling. Data entry will occur in the evenings. During the week, there will also be opportunities to engage with the local community and artisans.
    • One day will be reserved for lab work and to engage with the local kindergarten, elementary, or secondary school in Zorritos. Part of the day will be spent in the lab performing genetic analyses and zooplankton analyses; another portion of the day will be spent on outreach activities with local youth and students (e.g. mural painting, beach cleanups, etc.).
    • On the evening of Day 6, we will review achievements with a group activity.
  • Day 7: Team wrap-up in the morning, pack and depart for Tumbes Airport in the morning in time for early afternoon flights.


Accommodations and Food

You will be staying in a rented house that is located directly on the beach. The house is a 20-minute drive south from the town of Zorritos. The property is fenced in and is comprised of one main house with a kitchen and living area overlooking the ocean. The property also has three smaller cottages that contain bedrooms and shared bathrooms.

* Please note that not every expedition has couples’ or single's accommodations available. Please call or email Earthwatch to check for availability prior to reserving your space(s) on the team.


All bedding is provided. Please bring your own towels. Beds vary by room and are a mix of full and bunk beds. Each room can accommodate one to three individuals and will be divided by gender. The three sleeping cottages each have a shared bathroom with flush toilet and shower. Depending on team size and gender breakdown, single and couple room requests can be accommodated at no additional cost. NOTE: These requests will be on a first come first served basis.

* Earthwatch will honor each person’s assertion of gender identity, respectfully and without judgement. For both teen and adult teams, where logistics dictate single-sex accommodations or other facilities, participant placements will be made in accordance with the gender identity the participant specified on their Earthwatch Participant form and/or preferences indicated in discussions with Earthwatch.


There are three shared bathrooms with toilets and showers at the smaller cottages. The main house also has a simple bathroom with a sink and toilet. All showers are heated.


You are welcome to bring electrical equipment. Electrical outlets in Peru are 220 volts at 60 hertz. We recommend bringing an adapter for plug types A and C.


Wi-Fi is not available at this project site. If you wish to have access, you may consider contacting your phone company in advance to arrange for a data plan that will work in the region. Volunteers may connect to the Internet using staff hotspots for urgent communications only.

PIs and staff can be reached via telephone, cell phone, and email for emergencies. There is good cell phone coverage throughout the region, but most travelers will need an international service plan to place calls.

Please note that personal communication with outsiders is not always possible while participating in an expedition. Earthwatch encourages volunteers to minimize outgoing calls and immerse themselves in the experience; likewise, family and friends should restrict calls to urgent messages only.


For field days spent on the water, your team will drive to Zorritos (15–20 minutes away) to the town’s main fishing area on the beach. Once on the water, volunteers can expect to spend half the day on the boat performing plankton transects or searching for mantas.

One day will be spent in a nearby community, including working with a local school in Zorritos, among other activities.

Another half day will be spent doing lab work. This is just north of Zorritos and is approximately 30–35 minutes away from the accommodations.


Personal refrigerator space is available and can be used for medicine storage as needed.

Tap water is not drinkable, but large water jugs will be provided in the kitchen area. Water will also be available on the boats during fieldwork.

The following are examples of foods you may find in the field. Variety depends on availability. We appreciate your flexibility.

  • Breakfast: Bread, eggs, fresh fruit, cereal, toast, juice, and coffee.
  • Lunch and Dinner: Ceviche*, spaghetti with tomato sauce, sandwiches, chicken, and fresh salad.
  • Snacks: Fruit, cookies, crackers and/or chips.
  • Beverages: Fresh juice, water, coffee, and tea

*Ceviche is a local specialty, and has raw fish that is partially cooked by lemon/lime juice. Please be aware that there are inherent risks when eating raw seafood.


Please alert Earthwatch to any special dietary requirements (e.g., diabetes, lactose intolerance, nut or other food allergies, vegetarian or vegan diets) as soon as possible, and note them in the space provided on your volunteer forms.

Vegetarians can be accommodated on this project, if they are prepared to be flexible with food options. Usually there is plenty of food and meat can be avoided, with avocados and beans usually available to substitute protein. Processed vegetarian meat substitutes are not available. There is not much dairy included in the typical Peruvian diet so lactose intolerance should not be a problem. Gluten-free diets are more difficult to accommodate, but if volunteers are willing to bring supplemental food and/or purchase food when they arrive, the project will work with the volunteers to make this work.


Drinking is allowed in the evenings with meals, but this must be in moderation as we have an early start each day. Also, no smoking is allowed on the boats, in the project vehicles, and we ask that you be respectful of others and smoke outside when at the accommodations.

Project Conditions


For weather and region-specific information, please visit and search for your project location.


The project uses simple artisanal fishing boats operated by local fishermen made of wood and fiberglass. The vessels are fairly narrow and have canopy covers, but no heads (bathrooms). Bathroom breaks will be taken in the water. Water conditions should be relatively benign. You must wear a life jacket on the boat at all times.

Essential Eligibility Requirements

All participants must be able to:

  • Take an active role in your own safety by recognizing and avoiding hazards if and when they arise (including, but not limited to, those described in Earthwatch materials and safety briefings). Comply with project staff instructions and recommended safety measures at all times.
  • Be able to effectively communicate to the staff if you are experiencing distress or need assistance.
  • Be comfortable being surrounded by a language and/or culture that is different from your own.
  • Be able to get along with a variety of people from different backgrounds and ages, often in close proximity, for the duration of your team.
  • Follow verbal and/or visual instructions independently or with the assistance of a companion.
  • Wear all protective equipment recommended or required by industry standards.
  • Learn to make and record observations of mantas, behaviors, and habitats.
  • Be comfortable snorkeling in open water (for 10–15 minute intervals) in areas where volunteers can’t stand on the bottom, and be comfortable using snorkeling gear (mask, fins, snorkel). NOTE: it is also possible for volunteers to stay on the boat if they wish, but we ask that all volunteers be able to swim as a safety precaution.
  • The ability to swim is important for safety reasons as a large portion of the project is conducted from a boat and in the water. Volunteers that wish to assist with photographing mantas must be adept swimmers.
  • Enter and exit the water from small boats. A ladder will be available to make boat entry easier.
  • Work on or from a boat for about three to six hours per day with limited break options (e.g., no bathroom on the boat, except for the ocean).
  • Maintain a seated position within boat during transit, which can sometimes be bumpy. This can be uncomfortable for individuals with back problems or who experience seasickness.
  • Have good balance, especially when on the water. From the beach, volunteers will be ferried to the project boats via a small rowboat. Volunteers must be comfortable transferring and stepping between boats on the water.
  • Enjoy being outdoors all day in all types of weather. Weather can range from being very sunny and warm to cloudy and temperate.
  • Be able to get along with a variety of people from different backgrounds and ages, often in close proximity, for the duration of your team
  • Endure hot and cold work conditions. Peru is close to the equator, which means hot conditions and high sun exposure. Volunteers should bring layers, however, including a thin rain jacket/windbreaker, as the weather can be variable. Volunteers should also expect to get wet on the boat, which can lead to cooler conditions with wind or when the boat is in motion.

Health and Safety


The project will have cell phones and two-way radios for communication among the team while conducting fieldwork. When on the water, most locations have local cell reception. When service is unavailable, radios will be used instead.

Earthwatch has a 24-hour, 7-day-a-week emergency hotline number. Someone is always on call to respond to messages that come into our live answering service.


Please be sure your routine immunizations are up-to-date (for example: diphtheria, pertussis, tetanus, polio, measles, mumps, rubella and varicella) and you have the appropriate vaccinations for your travel destination. Medical decisions are the responsibility of each volunteer and his or her doctor. Visit the Center for Disease Control and Prevention or the World Health Organization for guidance on immunizations.

If traveling from countries or region where yellow fever is endemic, you must have a certificate of vaccination.

Project Risks and Precautions


Traffic accidents and injuries are always a hazard of road transport. Vans travel no faster than 55 kph on public roads. Every passenger will have a seat and must wear seat belts at all times. Volunteers must also take great care when crossing the street (highway), as traffic is dangerous in the area. Volunteers will not drive; only staff will operate vans and boats.


Volunteers must have good balance when they are on the water. Risks include sprains, strains, cuts or breaks due to falling or missteps. Project staff will highlight risks on site and curtail activities they judge too risky. At the accommodations, the pool area is also tiled and slippery when wet. Pool depths aren’t marked, and diving is not allowed. Volunteers should wear sandals/shoes when walking on the beach to avoid punctures/cuts from trash or thorns. The same is true for sandy areas on the accommodation’s property.


Mosquitoes are present in Tumbes, and repellent and pants can help protect from stings and bites. Man-o-wars and other jellyfish are also present, along with small stingrays near shore. Wetsuits and rash guards are recommended to avoid stings. Stray dogs are also present and should be avoided.

Lizards and geckos can be found around the accommodation. During the rainy season especially, Tumbes might be vulnerable to plagues of toads or crickets. All of these animals are harmless, but should not be touched.

There are also bigger docile species, like mantas and whale sharks. While these animals pose little risk, they are still large and must be respected when snorkeling. Volunteers should be aware of their positioning in the water to avoid collisions/abrasions with these animals. Project staff will advise on how to keep a safe distance from these species when in the water.


Tumbes weather is typically hot year round. Dehydration and sunburn are possible. You’ll be briefed on proper clothing, sunscreen use, and fluid intake. Project staff will set an example and monitor participants for symptoms of sun exposure and dehydration. Take particular care when working during the hottest periods of the day. You must come prepared with a light jacket or sweatshirt, as weather might also be cool during some periods.

Political, Social and Cultural

Project staff will advise you on local culture. They will also enforce appropriate clothing and footwear for particular situations, e.g., in town during the community/lab day. Volunteers should avoid wearing clothing that is too revealing.

Working on a Boat

Boats will have appropriate safety equipment, including a personal flotation device (PFD) for each passenger. You must wear PFDs at all times. Staff will brief the team on boating risks and precautions. You will be warned about potential waves, wet boat surfaces and the risk of sprains, strains, or breaks from falling on the boat.

Personal Security

Robbery is a risk outside of the project site, especially in Tumbes city. All bedrooms doors are lockable at the accommodations and volunteers will have access to the keys, which will be held by project staff. Use taxis instead of walking and always be aware of your surroundings. Avoid using the local motorcycle taxis and always opt for cars for transport.


Swimming is central to the research you’ll conduct and, possibly, during recreational time. Typical water-related risks are present. A certified lifeguard will not be available, but staff members have boat and first aid training. During recreational time, volunteers may not swim alone. Staff must be notified if volunteers wish to swim in the ocean. Night swimming is not allowed. Volunteers must also swim in pairs during recreational time.


Snorkeling has inherent risks, e.g., the effects of environmental conditions like nitrogen (for those who’ve recently scuba dived), barotrauma, boat traffic, marine life, and risks specific to one’s own physical history. When snorkeling, properly control your breathing to reduce the risk of hyperventilation and blackout. You must bring and maintain your own mask, snorkel, fins, booties, and exposure protection. The project PFDs can be used in the water for those who feel more comfortable snorkeling with them. You must ensure that all gear is in good working order and that you are trained in appropriate responses if a failure occurs while in the water.

On the first day of training, volunteers will be assessed on their swimming ability. Tasks will then be assigned accordingly, i.e. stronger swimmers will be needed for photographing the mantas. The Earthwatch scientist or support staff will be present in the water at all times with you. Swimming and snorkeling will only happen in calm seas. No one goes in—staff or volunteers—when an Earthwatch scientist or field team leader determines that conditions are unsafe.

Distance from Medical Care

The nearest basic medical center is a 20-minute drive from the accommodations. Air evacuation is required to reach the nearest fully equipped hospital, and it can take one hour to arrange transport to the nearest hospital. For more serious conditions, the nearest fully equipped hospital is 4–5 away in Piura—If you have a preexisting condition that could require immediate medical care (e.g., heart conditions, kidney problems, severe asthma), please discuss your participation with your physician.


Traveler’s diarrhea affects many international travelers. Diseases found in Tumbes may include Malaria, Typhoid and Hepatitis A. Please see the U.S. Centers for Disease Control and Prevention ( or the World Health Organization ( websites for more information on these conditions, and other localized diseases, and how to avoid them.

Travel Planning


Tumbes Airport, Peru

* Additional information will be provided by Earthwatch to meet your team. Please do not book travel arrangements such as flights until you have received additional information from Earthwatch.


Earthwatch strongly recommends that travelers investigate their destination prior to departure. Familiarity with the destination’s entry/exit requirements, visas, local laws, and customs can go a long way to ensuring smooth travel. The U.S. Department of State's Traveler’s Checklist and Destination Guides are helpful resources. For LGBTI travelers, the U.S. Department of State's LGBTI Travelers page contains many useful tips and links.


Entry visa requirements differ by country of origin, layover, and destination, and do change unexpectedly. For this reason, please confirm your visa requirements at the time of booking and, again, 90 days prior to travel. Please apply early for your visa (we recommend starting 6 months prior to the start of your expedition). Refunds will not be made for volunteers cancelling due to not obtaining their visa in time to meet the team at the rendezvous. You can find up to date visa requirements at the following website:

If a visa is required, participants should apply for a TOURIST visa. Please note that obtaining a visa can take weeks or even months. We strongly recommend using a visa agency, which can both expedite and simplify the process.

Generally, passports must be valid for at least six months from the date of entry and a return ticket is required.


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