Galapagos Species are Threatened By the Very Tourists Who Flock to See Them

by Veronica Toral-Granda, Charles Darwin University and Stephen Garnett, Charles Darwin University, The Conversation: https://theconversation.com/galapagos-species-are-threatened-by-the-very-tourists-who-flock-to-see-them-86392

Life’s not such a beach for Galapagos native species these days. shacharf/shutterstock

Native species are particularly vulnerable on islands, because when invaders such as rats arrive, the native species have nowhere else to go and may lack the ability to fend them off.

The main characteristic of an island is its isolation. Whether just off the coast or hundreds of kilometres from the nearest land, they stand on their own. Because of their isolation, islands generally have a unique array of plant and animal species, many of which are found nowhere else. And that makes all islands one of a kind.

However, islands, despite being geographically isolated, are now part of a network. They are globally connected to the outside world by planes, boats and people. Their isolation has been breached, offering a pathway for introduced species to invade.

The Galapagos Islands, 1,000km off the coast of Ecuador, provide a great example. So far, 1,579 introduced species have been documented on the Galapagos Islands, of which 98% arrived with humans, either intentionally or accidentally.

More than 70% of these species have arrived since the 1970s – when Galapagos first became a tourist destination – an average of 27 introduced species per year for the past 40 years.

New arrivals

Introduced species – plants or animals that have been artificially brought to a new location, often by humans – can damage native fauna and flora. They are among the top threats to biodiversity worldwide, and one of the most important threats to oceanic islands. The Convention on Biological Diversity has a dedicated target to help deal with them and their means of arrival. The target states that:

by 2020, invasive alien species and pathways are identified and prioritised, priority species are controlled or eradicated and measures are in place to manage pathways to prevent their introduction and establishment.

The Galapagos Islands are home to giant tortoises, flightless cormorants, and the iconic Darwin’s finches – species that have evolved in isolation and according to the differing characteristics of each of the islands.

However, the Galapagos’ natural attributes have also made these islands a top tourist destination. Ironically enough, this threatens the survival of many of the species that make this place so unique.

Humans on the rise

In 1950 the Galapagos Islands had just 1,346 residents, and no tourists. In 2015 more than 220,000 visitors travelled to the islands. These tourists, along with the 25,000 local residents, need to have most of their food and other goods shipped from mainland Ecuador.

These strengthening links between Galapagos and the mainland have opened up pathways for the arrival and spread of introduced species to the archipelago, and between its various islands.

Major species transport routes into and between the Galapagos Islands. PLoS ONE

More and more alien species are finding their way to the Galapagos Islands. PLoS ONE

Plants were the most common type of introduced species, followed by insects. The most common pathway for species introduction unintentionally was as a contaminant on plants. A few vertebrates have also been recorded as stowaways in transport vehicles, including snakes and opossums; whilst others have been deliberately introduced in the last decade (such as Tilapia, dog breeds and goldfishes).

The number, frequency and geographic origin of alien invasion pathways to Galapagos have increased through time. Our research shows a tight relationship between the number of pathways and the ongoing increase in human population in Galapagos, from both residents and tourists.

For instance, the number of flights has increased from 74 flights a week in 2010 to 107 in 2015; the number of airplane passengers has also increased through time with about 40% being tourists, the remainder being Galapagos residents or transient workers.

Global connections between Galapagos and the outside world have also increased, receiving visitors from 93 countries in 2010 to 158 in 2014. In 2015 and 2016, the Galapagos Biosecurity Agency intercepted more than 14,000 banned items, almost 70% of which were brought in by tourists.



We think it likely that intentional introductions of alien species will decline when biosecurity is strengthened. However, with tourists as known vectors for introduced species and with tourism much the largest and fastest growing sector of the local economy, unintentional introductions to Galapagos will almost certainly increase further.

If islands are to be kept as islands, isolated in the full sense of the word, it is of high priority to manage their invasion pathways. Our research aims to provide technical input to local decision makers, managers and conservation bodies working in Galapagos in order to minimise a further increase on the number of available pathways to Galapagos and the probable likelihood of new arrivals. Our next step is to evaluate how local tourism boats are connecting the once isolated islands within Galapagos, as a way to minimise further spread of harmful introduced species to this UNESCO World Heritage Site.

Veronica Toral-Granda, PhD candidate, Charles Darwin University and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University

This article was originally published on The Conversation. Read the original article.

Citizen Scientist Scuba Divers Shed Light on the Impact of Warming Oceans on Marine Life

by Madeleine De Gabriele, The Conversation: https://theconversation.com/citizen-scientist-scuba-divers-shed-light-on-the-impact-of-warming-oceans-on-marine-life-85970

Rising ocean temperatures may result in worldwide change for shallow reef ecosystems, according to research published yesterday in Science Advances.

A volunteer diver surveys marine life at Lord Howe Island. Rick Stuart-Smith/Reef Life Survey, Author provided

The study, based on thousands of surveys carried out by volunteer scuba divers, gives new insights into the relationship of fish numbers to water temperatures – suggesting that warmer oceans may drive fish to significantly expand their habitat, displacing other sea creatures.

Citizen science

The study draws from Reef Life Survey, a 10-year citizen science project that trains volunteer scuba divers to survey marine plants and animals. Over the past ten years, more than 200 divers have surveyed 2,406 ocean sites in 44 countries, creating a uniquely comprehensive data set on ocean life.

Reef Life Survey takes volunteers on surveying expeditions at hard-to-reach coral reefs around the world. Rick Stuart-Smith/Reef Life Survey, Author provided

Lead author Professor Graham Edgar, who founded Reef Life Survey, said the unprecedented scope of their survey allowed them to investigate global patterns in marine life. The abundance of life in warm regions (such as tropical rainforests and coral reefs) has long intrigued naturalists. At least 30 theories have been put forward, but most studies have been based on relatively limited surveys restricted to a single continent or group of species.

By tapping into the recreational scuba diving community, Reef Life Survey has vastly increased the amount of information researchers have to work with. Professor Edgar and his colleagues provide one-on-one training to volunteers, teaching them how to carry out comprehensive scans of plants and animals in specific areas.

Dr Adriana Vergés, a researcher at the University of New South Wales specialising in the impact of climate change on ocean ecosystems, said that the Reef Life Survey has already substantially improved our understanding of the marine environment.

“For example, Reef Life Survey data has greatly contributed to our understanding of the factors that determine the effectiveness of effectiveness of marine-protected areas worldwide. The team have made all their data publicly available and more and more research is increasingly making use of it to answer research questions,” she said.

Some of the divers have been working with Reef Life Survey for a decade, although others participate when they can. One volunteer, according to Professor Edgar, was so inspired by the project that he began a doctorate in marine biology (he graduated this year).

There’s a strong link between fish numbers and water warmth, which means warming oceans are likely to change global fish distribution. Rick Stuart-Smith/Reef Life Survey, Author provided

Warming oceans means fish on the move

One of the important insights delivered by the Reef Life Survey datatbase is the relationship between water temperature and the ratio of fish to invertebrates in an ecosystem. Essentially, the warmer the water, the more fish. Conversely, colder waters contain more invertebrates like lobster, crabs and shrimp.

Professor Stewart Frusher, director of the Centre for Marine Socioecology at the University of Tasmania (and a former colleague of Professor Edgar) told The Conversation that he believes we will see wide-scale changes in fish distribution as climate change warms the oceans.

“Species are moving into either deeper water or towards the poles. We also know that not all species are moving at the same rate, and thus new mixtures of ecosystems will occur, with the fast-moving species of one ecosystem mixing with the slower moving of another,” he said.

As species migrate or expand into newly warmed waters, according to Professor Frusher, they will compete with and prey on the species already living in that area. And while it’s uncertain exactly how disruptive this will be, we do know that small ecosystem changes can rapidly lead to larger-scale impacts.

In order to predict and manage these global changes, scientists need reliable and detailed world-wide data. Professor Frusher said that, with research funding declining, scientists do not have the resources to monitor at the scales required.

“Well-developed citizen science programs fill an important niche for improving our understanding of how the earth is responding to change,” he said.

Madeleine De Gabriele, Deputy Editor: Energy + Environment, The Conversation

This article was originally published on The Conversation. Read the original article.