Connect with us

Feature Destination

At Unguja Ukuu, Human Activity Transformed The Coast of Zanzibar More Than 1,000 Years Ago

The medieval settlement of Unguja Ukuu, on the Zanzibar Archipelago off the coast of Tanzania, was a key port in an extensive Indian Ocean trade network that linked eastern Africa, southern Arabia, India and Southeast Asia.

Our archaeological research shows how human activities between the seventh and twelfth centuries AD irreversibly modified the shoreline around the site. At first, these changes may have helped the trading settlement develop, but later they may have contributed to its decline and abandonment.

Ancient seafaring

For millennia, the Indian Ocean has been the maritime setting for an early form of globalisation. Large trade networks operated across the vast ocean, foreshadowing modern global shipping networks. Unguja Ukuu was a crucial location in this early trade and an important node in the nascent slave trade out of continental Africa.

Unguja Ukuu was an active settlement from the mid-first millennium until the early second millennium AD. Archaeological evidence and historical accounts suggest Unguja Ukuu is one of the earliest known trading settlements on the Swahili coast.

The rise and fall of trading ports

To understand how and why early ports thrived or declined, it is important to know how the coastal landscape influenced the way traders operated. This includes their choice of mooring locations and their connections to inland locations. 

But the question of how these commercial activities in turn modified the coastline has received less attention.

Satellite image of the location of Unguja Ukuu and the surrounding landscape. Insets: A) the extent of the tidal channel leading to the settlement; B) satellite view of the settlement site; c) the Uzi channel leading towards the creek. Illustration by Juliën Lubeek. GoogleEarth, Author provided

Unguja Ukuu prospered in an ecologically marginal zone, hemmed in between the sandy back-reef shore of Menai Bay and mangrove-banked creeks to the east. 

Menai Bay afforded shelter from monsoonal storms and navigable waterways across the shallow inner shelf to the shore. It also provided food and other materials from the mangrove habitat. 

This landscape enabled the emergence of the farming, fishing, and trading settlement of Unguja Ukuu.

Sediment, sand and shells

We studied sediments, back-beach sands, and shells at Unguja Ukuu to understand how the settlement had affected its own environment. We found the accumulation of coastal sediments over centuries led to significant changes in the landscape.

Detritus from the settlement, such as food remains, hearths and other domestic waste, helped the beach spread outward into the sea. Our analyses show how human waste and the compaction of ancient surfaces drove the coastline change, supporting the emergence of a major trading site.

Photograph of the north section of Trench UU14 with a schematic representation of facies. and the interpretations of the anthropogenic signatures in the sediments. Author provided.

As more land was used for urban living and agriculture, more sediment moved from the land to the sea. This contributed to rapid growth of beach fronts, physically altering the coastal landscape and the ecological conditions of the adjacent sea-scape. 

These changes in turn could have resulted in habitat shifts and silting of the lagoon which possibly contributed to Unguja Ukuu’s decline. 

Early human impacts

Human-made processes might also be implicated in the decline and eventual abandonment of Unguja Ukuu in the second millennium AD. This was an important period in the socio-political and economic transformation of coastal African societies, marking the emergence of maritime Swahili culture. 

But suggesting a purely environmental cause for the settlement’s abandonment would be too simplistic. The interaction of coastal villages and harbours with their dynamic landscapes may have had a role in this regional reorganisation of settlements, harbours, and trade flows.

New advances in archaeological science techniques, combined with systematic archaeological analyses, are increasingly allowing us to disentangle natural from human-made drivers of events. Such work often reveals far earlier human impacts than once envisioned, shedding light on the early roots of Earth’s current geological epoch: the Anthropocene, in which human activity is a key force reshaping the planet. 

Human-made soil

Our work records snapshots of the evolution of a natural coastal system at the fringes of an early settlement. 

River sediments were covered by beach sands containing increasing amounts of human waste accumulating from the mid-seventh century AD. This backshore activity area was used for small-scale subsistence activities (including processing shells for meat), trade, and the dumping of industrial waste. 

Earlier urban development shaped Unguja Ukuu’s soils over the long term and through periods of settlement decline and abandonment from the twelfth century AD onwards. A dark earth “anthrosol” (human-made soil) continues to evolve on these archaeological deposits today, supporting cultivation in and around the modern town.

Dark human-made soils such as these, formed by the rapid decay of organic- and phosphate-rich waste from the settlement, may be used as markers for as-yet-undiscovered archaeological sites on the eastern African coast. Their distinctive dark colour renders the soils easily identifiable on satellite images and other remote-sensing datasets.

Understanding the past to shape the future

Our study clearly shows how human modification of natural environments affected coastal landscapes on an East African island more than 1,000 years ago. These findings are a reminder that humans have been changing our environment for thousands of years – sometimes for the better, and sometimes for the worse. 

Studying history and archaeology is not simply about learning from our ancestors’ mistakes so that we don’t repeat them. It is also about ensuring that scientifically rigorous data that show how human activity in the past often altered the landscapes and environments in which people lived is effectively communicated, to both governments and the public. 

If we can do this we might be able to make better informed sustainable choices for the future of our planet.

See the original post here…


Continue Reading

Feature Destination

Feature Destination: A Conservationist’s Reflection on Family, Biodiversity, and Restoration in Costa Rica

Costa Rica is one of the few countries I’ve returned to repeatedly over the last twenty or so years. Each visit has reinforced why this small Central American nation continues to hold a special place in my heart. As a conservationist, I’ve long admired its bold environmental policies, its ability to restore vast areas of degraded land, and the extraordinary biodiversity that thrives here. But what draws me back just as strongly is the feeling that Costa Rica gives you: the quiet assurance that another world is possible, one where people and nature can coexist with purpose and respect.

I had the chance to experience Costa Rica in a new way, traveling with three generations of my family. My husband, my sister and her family, and our aging parents all came together for what we knew would be a once-in-a-lifetime trip. My sister chose Costa Rica not only because of its beauty, but also because it felt manageable for a multigenerational vacation. It’s safe, accessible, and well set up for travelers of all ages. We also understood it would be expensive, but for the chance to travel together as a full family, the investment was worth it.

coconut tree on beach shore during daytime

We started our journey in San José, where my husband and I stayed in a homestay with a Costa Rican grandmother. She greeted us with warmth, fed us incredible meals, and gave us our first taste, quite literally, of the hospitality this country is known for. From there, we headed to Quepos on the Pacific coast, where my sister had rented an Airbnb home. It was the perfect setup with a space for all of us to gather, cook, relax, and look out over a small deck that faced what appeared to be pure jungle. The view was mesmerizing. We later learned that only a few decades ago, the entire landscape had been logged and used for farmland or extraction. But thanks to Costa Rica’s climate and commitment to restoration, nature had returned with full force. You’d never know it had once been stripped bare.

Every morning, we gathered on that deck before sunrise with coffee in hand to watch the forest awaken. Birds darted through the trees: tanagers, flycatchers, motmots, flickering colors between the leaves. For a family of nature lovers, those quiet hours became some of the most meaningful and memorable moments of the entire trip.

Quepos gave us easy access to both the coast and the rainforest. We hiked in the nearby parks, explored waterfalls, we stumbled on eco-tours of chocolate-making, coffee farming, and sustainable agriculture. The excursions were varied and accessible. Canopy walks, guided nature trails, and small boat rides. Costa Rica’s dynamic geography from the mountains, coasts, volcanoes, and rainforests means you don’t have to travel far to experience completely different ecosystems.

Although my husband and I skipped diving this time to stay together as a family, we did take a longer boat ride to a more remote patch of primary forest. I believe we were on the edge of the Osa Peninsula or near Corcovado National Park, which is known as one of the most biologically intense places on Earth. The experience reminded me again how rare it is to be able to witness truly untouched rainforest.

Every meal we ate was exceptional. With such a strong agricultural foundation, the food was consistently fresh, flavorful, and locally grown. Pineapple, avocado, coffee, papaya, rice, and beans, all vibrant and prepared with pride. Costa Rica’s commitment to sustainable agriculture shows in the taste of what ends up on your plate.

Beyond the beauty and comfort, what continues to impress me most is Costa Rica’s national commitment to conservation. Despite being only about 51,000 square kilometers in size, Costa Rica is home to more than 500,000 species, about 5% of the world’s biodiversity, thanks to its location at the intersection of North and South America. The diversity includes iconic species like the resplendent quetzal (Pharomachrus mocinno), Baird’s tapir (Tapirus bairdii), jaguars (Panthera onca), and endangered sea turtles like the green sea turtle (Chelonia mydas), which nests on the Caribbean coast in places like Tortuguero National Park.

gray wooden bridge in forest during daytime

Costa Rica has not only preserved what it has, it has reversed damage from generations of less sustainable development. In the 1980s, deforestation was rampant, with forest cover reduced to about 21%. But thanks to a range of government policies, including the 1997 launch of the Payment for Environmental Services (PES) program, forest cover has increased to over 50% as of the 2010s, and as of 2022 forests covered approximately 60.1% of the country’s land area, according to the World Bank. The PES program rewards landowners for keeping forests intact, recognizing the economic value of ecosystem services such as carbon capture, water filtration, and biodiversity protection. Much of this work is administered through MINAE (the Ministry of Environment and Energy), and its subsidiary agencies like SINAC, FONAFIFO, and CONAGEBIO.

gray and brown turtle on gray sand during daytime

The country has also turned its attention toward marine conservation, with over 30% of its territorial waters now designated as marine protected areas (MPAs). These include coral reefs, mangroves, and marine corridors vital for species like sharks, whales, and sea turtles. Organizations like the MarViva Foundation have been instrumental in managing these MPAs, particularly around the Eastern Tropical Pacific.

Folks from Costa Rica, also called Ticos, have the reputation of being affectionately warm, proud, and deeply connected to the land. You quickly learn the phrase “Pura Vida” is more than a slogan. It’s a mindset, an expression of gratitude, resilience, and appreciation for life’s simple gifts. It’s said as a greeting, a farewell, a thank-you, and always with a smile.

Traveling here, you’ll find that Costa Rica is not only logistically easy, but emotionally and intellectually enriching. Whether you’re a solo traveler, a couple, or a multigenerational family like us, there’s something for everyone. The country is incredibly welcoming to people of all backgrounds, and it’s one of the safest places in Central America to visit.

If you’re planning a trip, the best advice is to decide what kind of experience you’re looking for. Do you want to immerse yourself in the jungle? Lounge on the beach? Explore volcanoes? Stay in a city and do day trips? Or do a bit of everything? There’s no single way to “do” Costa Rica. You can rent a car or rely on shuttle services. Stay in a city hotel, a remote eco-lodge, or a beachside Airbnb. It’s all possible.

Here are a few key regions to consider:

  • Central Valley (San José and surroundings): Cultural sites, museums, and access to volcanoes and cloud forests.

  • Pacific Coast (including Quepos and Manuel Antonio): National parks, beaches, and adventure tourism.

  • Caribbean Coast (like Puerto Viejo and Tortuguero): Afro-Caribbean culture, nesting turtles, and rich biodiversity.

  • Northern Plains (Arenal and La Fortuna): Hot springs, waterfalls, and volcanoes.

  • Southern Zone (Osa Peninsula and Corcovado): Pristine rainforest, rare species, and incredible biodiversity.

VisitCostaRica.com is the official tourism website and a helpful starting point for researching regions, accommodations, and activities.

For us, this trip was a chance to reconnect, not just with each other, but with the natural world. Costa Rica has a way of doing that. When you’re surrounded by howler monkeys at dawn, or listening to rain fall onto leaves the size of couch cushions, or catching a glimpse of a toucan in flight, you remember what it feels like to be part of something ancient and alive.

And in a world where conservation so often feels like a losing battle, Costa Rica shows what can be achieved when a nation decides to prioritize nature, not just in words, but through action.

Continue Reading

Feature Destination

Feature Destination – Journeys With Purpose: Restoring Island-Ocean Ecosystems in Palau

Journeys With Purpose (JWP)

Visiting Palau has been one of the most remarkable and affirming experiences of my life.  Spending hours in the ocean observing turtles, sharks, rays and a host of other marine species, including cuttlefish changing colour and form to their immediate environment, has proven to be one of the greatest joys and wonders in the world.

I grew up watching and entranced by the TV series ‘The Undersea World of Jacques Cousteau’.  Such was the impression Cousteau’s series made on me, as a very young child my first pet was called ‘Calypso’, after his fabled research vessel. My experiences in Palau brought back these vivid memories directly. With a particular snorkelling experience on this journey, a fellow traveller commented that this must be “the day you fell in love with sharks” – and it truly was.

Throughout the course of the last 12+ months, Journeys With Purpose has worked alongside the world-class organisations of Island Conservation and Scripps Institution of Oceanography, in association with Re:wild, on a ‘Restoring Island-Ocean Ecosystems’ journey to champion and support the Island-Ocean Connection Challenge (IOCC). 

The IOCC aims to restore at least 40 globally significant island-ocean ecosystems from ridge to reef by 2030 to benefit people, wildlife and our planet.  This goal is delivering tangible action and successes, and signifying more widely the essential connection between island health and ocean health. Holistically restoring islands delivers outsized benefits for wildlife, oceans, people and climate impacts.  

Key IOCC messages:

  • Healthy oceans need healthy islands
    • island and marine ecosystem elements cycle into one another, sharing nutrients vital to the plants and animals within them. Invasive species damage these fragile ecosystems and work to remove these in order to  restore balance and endemic species such as the Megapode bird is vital.
  • Everything is connected – Indigenous Peoples and local communities know this
    • Indigenous Peoples and local communities have long understood and managed their natural resources in the context of island-to-sea connections. As Wayne Andrew, Micronesia Director of OneReef says “Community is not people alone. Community is a place, the reef. The respect of all that is so important”. This is rooted in their traditional knowledge and wisdom, including ancient oral stories such as the “Megapode Bird and Hawksbill Turtle”.  It is essential to support local leadership and communities in the decisions they wish to make to protect these vital ecosystems.
  • Collaboration is essential
    • taking a collective approach to sustainable science and the importance of collaboration with local communities to achieve more holistic results.
  • Emerging Science and Impact Monitoring
    • global scalability of work informed by science. Emerging research shows people, wildlife and marine environments benefit when island-ocean connections are restored.
  • Islands are on the frontline of environmental crises
    • a staggering 41% of critically threatened species are found on islands
    • 27% of all languages come from island communities
    • surrounding coral reefs are home to 25% of all marine life

We travelled with leadership from Palau’s local communities, Island ConservationScripps Institution of Oceanography and supporters of these organisations. The collective experience of our time with these communities, and snorkelling and diving, was quite remarkable – a true spirit of togetherness and bonding developed that we will treasure for the rest of our lives. And importantly to take forward into action.

My key takeaways are thus:

  • People make Places
    • this is never more true than in Palau. There are approximately 20,000 local inhabitants on Palau’s islands, and they demonstrate an incredible bond, cohesiveness and strength together. This is brilliantly encapsulated by the local Hatohobei community, who rejected sizeable bribes to thwart a significant illegal fishing operation – “… we’re doing it for our people, for the future generations.”
  • Impact at Scale
    • the Palau National Marine Sanctuary (PNMS), effective 1 January 2020 with support from the Palauan government and several NGOs, is one of the largest marine protected areas (MPA) in the world.  It was the first MPA of its kind, protecting 80% of a country’s national waters in a fully protected no-take zone. 
    • the PNMS protects a vast array of marine life and unique geological features within its over 475,000 km2, an area larger than Germany, Japan, Iraq, Sweden, etc. Eight hundred marine vertebrate species call the PNMS home, including nearly 30 different marine mammals and 60 shark and ray species, though these numbers are likely underestimated, as the biodiversity of the PNMS remains understudied.  
    • all achieved with the spirit of just 20,000 Palauans.
  • Be Brave
    • as above, the Palauans have been incredibly brave in their approach with their communities, natural environment and ambition. Very sadly, this is not the norm around the world, but is, however, a lesson for us all – trust our hearts and do the right thing to help deliver today a viable future. We must turn the currency of hope into the currency of action.

I have observed these three takeaways in the great conservation and rewilding endeavours around the world.  It can be done. I urge us all, in the strongest possible manner, to support the work of the people of Palau, Island Conservation and Scripps Institution of Oceanography – brilliant people, doing brilliant work, in brilliant places.   My eternal gratitude to our partners and supporters on this journey, and in particular to the exceptional dedication, hospitality and warmth of our local Palauan partners at Island Conservation PalauEbiil SocietyOneReef, Koror State DCLE (Department of Conservation and Law Enforcement), Ngarchelong State Rangers and many others.   Palau, officially the Republic of Palau, is an island nation in the Micronesia region of Oceania in the western Pacific, comprising an archipelago of over 350 islands.  Little known to many of us, it is one of the most remarkable ecosystems and communities on Earth.  Please connect here – connect@journeyswithpurpose.org – to understand how you can contribute, and visit Palau. 

A tribute to the people of Palau:-  in memoriam to Prince LeeBoo of Palau, 1763 to 1784.

With the consent of his father King Ibedul of Koror, Prince LeeBoo departed Palau with Captain Henry Wilson and the crew of the Antelope to London, England on 12 November 1783.  Whilst in London, Prince LeeBoo became Palau’s de facto ambassador of goodwill to England, and a scholar.  However, LeeBoo’s plan of returning to Palau to spread knowledge and scientific discoveries to his people ended abruptly when the young prince succumbed to smallpox in the winter of 1784.  The remains of Prince LeeBoo and his plans lay buried today in the courtyard of St. Mary’s church in Rotherhithe, London, England.

Despite the dilapidation of time, the spirit of Prince LeeBoo continues to live in the hearts of the people of Palau – their immense strength of community, positive impact and fortitude.  His story, and purpose in life, remains widely told amongst the people of Palau today.  

This article was retrived from Duncan’s Field Notes.

Journeys With Purpose offers immersive conservation and ethical travel experiences. Through private and hosted trips with pioneering conservationists, guests experience rewilding and restoring biodiversity in the wildest corners of the world. Our “Seven Worlds, One Planet” approach is a global curriculum focused on recovering and conserving vibrant landscapes, biodiversity, wildlife and livelihoods across all seven continents.

Journeys With Purpose (JWP)

Continue Reading

Feature Destination

Feature Destination: Discovering the Delicate Balance of Palau’s Jellyfish Lake Ecosystem

Jellyfish Lake, or Ongeim’l Tketau, nestled within the Rock Islands of Palau, is one of the world’s most captivating marine environments. This small, isolated lake on Eil Malk Island has become an emblem of both natural wonder and environmental vulnerability. Covering approximately 12,000 square meters, it is connected to the ocean through subterranean limestone channels, but remains sufficiently secluded to have evolved a delicate and distinct ecosystem. Among its most celebrated inhabitants are the golden jellyfish (Mastigias papua etpisoni) and moon jellyfish (Aurelia sp.), which have adapted to their surroundings in unique ways. These golden jellyfish are known for their daily sun-following migration, a behavior designed to maximize exposure for the symbiotic algae within their tissues, a remarkable example of the interdependence that thrives in marine environments.

The lake’s fragile ecosystem, however, has not been immune to change. Environmental stressors, particularly those tied to global climate phenomena, have repeatedly threatened the jellyfish population. In 2016, a severe El Niño-induced drought led to a dramatic decline in the number of golden jellyfish, forcing authorities to close the lake temporarily to tourism. The population eventually began to recover, and by 2018 the lake was reopened. Yet, the pattern of fluctuation has continued. As of early 2025, fewer than 5,600 golden jellyfish were recorded in the lake, an alarming drop from the millions typically present. Scientists and conservationists attribute the current decline to elevated water temperatures that disturb the sensitive balance within the lake, raising concerns about long-term impacts on this unique ecosystem.

Despite these challenges, Jellyfish Lake remains a focal point for ecotourism, conservation, and scientific inquiry. Visitors from around the world still make the journey to snorkel alongside its otherworldly inhabitants, although strict regulations are in place to protect the site. Scuba diving is prohibited to avoid disrupting the stratified lake layers, particularly the lower ones, which contain hydrogen sulfide toxic to both humans and jellyfish. Sunscreen and body products are also discouraged to prevent contamination. Entry permits issued by the Koror State Rangers help regulate foot traffic while funding ongoing conservation and research efforts.

Palau’s approach to conservation extends far beyond Jellyfish Lake. In January 2024, the country became the first to ratify the High Seas Treaty, a groundbreaking international agreement designed to protect ocean areas beyond national jurisdiction. This commitment is a continuation of Palau’s long-standing environmental leadership, exemplified by its establishment of one of the world’s largest marine sanctuaries and its ongoing dedication to preserving marine biodiversity. In the context of these broader efforts, Jellyfish Lake becomes more than a tourist destination, it is a symbol of resilience and a living case study in the interconnectedness of environmental health and global climate change.

Travelers to Palau are often enchanted not only by Jellyfish Lake but also by the vast natural and cultural riches of the archipelago. From the iconic Blue Corner dive site teeming with sharks and manta rays to the tranquil beauty of the UNESCO-listed Rock Islands, Palau offers a wealth of immersive experiences. The country’s cultural history also plays a vital role in the visitor experience, with ancient stone monoliths, traditional architecture, and community-led crafts inviting deeper engagement with the island nation’s heritage.

As we grapple with the accelerating impacts of climate change and environmental degradation, places like Jellyfish Lake underscore the urgency and value of robust conservation efforts. The fluctuations in jellyfish populations reflect a broader ecological volatility that is no longer confined to isolated ecosystems. Palau’s stewardship of its marine environments, through policy, tourism regulation, and global advocacy, serves as a model for balancing human engagement with environmental responsibility. In preserving Jellyfish Lake, Palau preserves not just a unique species or a popular destination, but a profound story about nature’s fragility and the shared responsibility to protect it.


Continue Reading

Trending

Copyright © 2025 SEVENSEAS Media Giacomo Abrusci