I recently helped to organise an environmental meeting and found myself checking our video link by calling home. Beamed on to the screen was my four-year-old son, hair sticking out and school jumper on back to front. As we checked the sound, I asked him what message he would like to send. Without hesitation he said: “Why do people have to throw rubbish in the sea and hurt marine creatures?” His worried little face, now filling the 2m-wide screen, stayed with me throughout the meeting (along with the hope that he’d turned his jumper round before going to school).

His message was with me again as I watched distressing footage of thousands of dead starfish and other creatures washed up on the beaches of Kent and the east coast. Conservationists believe last week’s freezing weather was behind the mass die-off.

We need to tell our children about the harm humans do, but also show how everyone can help look after the oceans

Like many people, my son is really anxious about the damage we are doing to our seas. He still loves exploring rock pools, and watches Blue Planet episodes over and over again with his equally sea-loving grandad. But I’ve realised I need to work to instil in him some optimism to counter his anxiety.

Fortunately, there are good reasons for hope. I remember a 2009 conference in Washington DC, where the marine scientist Sylvia Earle gave a keynote address about “hope spots” – her term for special places around the world where conservation work has particular ecological, cultural or community importance.

In the decade since then, Earle and others have taken this message around the world, as part of a wider movement to promote the idea that it is not too late to act to protect our global marine ecosystems. The first Conservation Optimism Summit event was held in London last year, co-hosted by the Zoological Society of London, Oxford University and the Durrell Wildlife Conservation Trust.

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Facebook Twitter Pinterest ‘It is not too late to act to protect our global marine ecosystems.’ Sylvia Earle on World Oceans Day 2017. Photograph: Kim Haughton/UN Photo

There are some great stories about how good science, international co-operation and community engagement have saved species and habitats. In 1979, for example, there were less than 100 Rodrigues fruit bats left on the Indian Ocean island that gives them their name. Thanks to decades of conservation efforts, both locally and internationally through zoo-breeding programmes, there are now more than 20,000 in the wild. As they fly out from their forest homes at dusk to forage for fruit, they symbolise real hope for those who are working to save species on the edge.

But conservation success isn’t just about saving rare creatures, or wonders of the world such as tigers and coral reefs; initiatives to improve people’s everyday interactions with nature can happen almost anywhere, and are vital in shaping a future in which people and nature can co-exist. Urban gardens can increase biodiversity; communities can resurrect forgotten traditions and indigenous knowledge to reconnect with their local environments; and teachers can inspire and influence the behaviour of entire generations.

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We need to face and understand environmental problems to be able to solve them, but despair alone doesn’t lead to positive outcomes. It is easy to become overwhelmed by the vastness of the task of reversing the alarming damage to so many aspects of the natural world. We need stories about people working together to make a difference to inspire our own small steps.

Children are bombarded with stories of the ocean’s demise, whether it’s news about plastic pollution, or coral bleaching on BBC children’s programmes such as Octonauts. They need to know there are some happy endings. My son understands that if he doesn’t drop litter, and explains to his friends why this is important, their behaviour will directly benefit the marine nature reserve in the bay where we live.

I recently attended a community screening of the film A Plastic Ocean. With a potent mix of horror and hope, the film shows the extent of the problem but also highlights what we can all do to help. We need to tell our children about the harm humans do, but also about where special habitats have been protected, and show how everyone can do something to help look after the oceans.

• Fiona Gell is a marine conservation officer