The June wind comes in from the mouth of the Luoyang River, heavy with sea moisture. Standing again on the stone slabs of Luoyang Bridge, I looked down at the mangroves below. In the morning light, the dense green seemed almost black, shining quietly along the tidal flat.
There are several familiar mangrove species here in southern Fujian: Kandelia obovata, Avicennia marina, and Aegiceras corniculatum. They grow shoulder to shoulder, their viviparous seedlings hanging from the mother plants like strings of small exclamation marks. When the tide rises, seawater covers their roots and leaves only the glossy crowns visible. When it ebbs, the prop roots and breathing roots emerge, packed close together, weaving a brown net across the mud.
Thirty years ago, when I first began working in ecological and environmental protection, this mangrove forest was far less vigorous. Along the shores of Quanzhou Bay, embankments built for marine aquaculture cut across the tidal flats like scars. Domestic wastewater flowed directly into the sea, and the mangroves were retreating year by year. An old fisherman once told me, “When I was a child, we caught mudskippers here. The trees were taller than our heads. Later, there were fewer and fewer of them.” As he spoke, the wrinkles at the corners of his eyes looked much like the gullies left behind on the mudflat after the tide had gone out.
After three decades in environmental work, I have come to feel that ecology is not only a science. It is also a kind of philosophy—a philosophy of balance. The Earth has an ability to heal itself, but that ability has limits. It is like a spring: press it down lightly, and it can still rebound; push it too far, and it may never return to its original shape.
The improvements in air quality over the years are something ordinary people can see and feel. Desulfurization and denitrification in industrial boilers, along with the wider use of new-energy vehicles, have helped turn skies that were once gray back toward blue.
Water management has offered even more lessons. One practical experience has become increasingly clear: domestic sewage can often be treated locally through soil-based systems. In rural areas, the three-chamber septic tank used by individual households is among the simplest forms of decentralized treatment. Industrial wastewater, however, must first be collected and pretreated before being sent to urban wastewater treatment plants for centralized processing. It is much like the human body: small ailments can sometimes be handled by the immune system, but serious illness requires a hospital.
The recovery of the mangroves at Luoyang Bridge is perhaps the clearest illustration of this way of thinking. The bridge, a stone sea-port bridge built during the Northern Song dynasty, and the mangrove ecosystem, an ancient living system that has evolved over millions of years, coexist in the same bay. Together they form a quiet model of harmony. The boat-shaped pointed foundations of the bridge piers reduce the force of tidal currents, while the mangrove roots help stabilize the mudflats and lessen silt movement.
But even here, balance matters. Silt cannot simply be ignored forever; it needs appropriate clearing. Soil, too, needs to breathe. Leave everything entirely untouched, and problems can still accumulate. Again, the key word returns: balance.
Every World Environment Day, this truth becomes especially clear to me: in the end, environmental protection is not about saving the Earth. It is about saving ourselves. The planet does not need rescue in the way we often imagine. It has endured conditions far worse than those we know today—atmospheres transformed beyond recognition, mass extinctions across the living world—and over millions of years it has repaired itself again. The ones who cannot withstand such upheaval are human beings.
Looking out from Luoyang Bridge at dusk, the setting sun turns the sea gold. Egrets return to their nests in the mangroves. On the tidal flats below, small fiddler crabs busy themselves, one oversized claw raised like a flag. At the far end of the bridge, the high-rises of Quanzhou are faintly visible. A modern city, a thousand-year-old stone bridge, and a seemingly primeval mangrove forest stand together in a calm, unforced coexistence.
I once remembered a student asking me during an ecological survey along the Luoyang River more than twenty years ago, “Teacher, when do you think the environment will get better?” At the time, I did not answer directly. Now I think the answer is not that the environment must return to some untouched original state. Improvement means finding a dynamic balance within development.
Pristine ecosystems must be protected, but people also need to live. The way forward lies in adapting to local conditions. The builders of Luoyang Bridge understood how to use oysters to reinforce the bridge foundations. In our time, we must also learn to use wisdom—so that cities and ecosystems can each find their proper place and, in the end, make peace with one another.
Night gradually deepens. Lights from the city appear in the distance and scatter across the sea as trembling fragments of brightness. Walking back from the bridge, I thought of the thirty years already spent in this work, with all its hardships and mixed rewards. Yet seeing these mangroves slowly return, I felt that it had all been worthwhile. The June sea breeze touched my face, salty as ever, but unusually fresh.