A wetlands ecologist and president of Lewis Environmental Services, Inc., Lewis specializes in the ecology, management, restoration and creation of fresh and saltwater marshes, mangrove forests, forested freshwater wetlands, and seagrass meadows. Robin has applied his expertise to hundreds of projects throughout the world, and to more than 100 papers on the subject of wetland restoration. He is the president of Coastal Resource Group, Inc., a non-profit educational and scientific organization and the force behind the resource-filled web sites www.mangroverestoration.com and www.seagrassrestorationnow.com. Robin is so passionate about the need to pass the torch to the next generation of coastal wetland restoration professionals, he has voluntarily taught courses on the subject for the U.S. Army Corps of Engineers, Ohio State University, University of Wisconsin and Louisiana State University. He has also taught wetland restoration in twenty-two foreign countries including Guyana, Jamaica, Bonaire, Nigeria, India, Sri Lanka, Thailand, Indonesia and Vietnam. He has served on the boards of the Society of Wetland Scientists, Association of State Wetland Managers, Mangrove Action Project, WildLaw, Inc., and the Putnam County Environmental Council. Last year, he was appointed to the IUCN’s Species Survival Commission Mangrove Specialist Group.
Are some coastal habitats easier to restore than others? Why?
In a 2011 paper that was published in the National Wetlands Newsletter, I created a hierarchy showing the likelihood of successful restoration. At the top are estuarine marshes and mangroves. At the bottom is submerged aquatic vegetation. From my experience, I have seen that the chances of success with sea grass restoration are very low.
Why is that?
With coastal wetlands, the key driving force for success is whether you can get the hydrology right at your restored sight. Hydrology in coastal systems is generally predictable. When I teach the subject, I tell my students that on my computer I have a program that gives me the tides for several hundred locations around the world—going back and forward 100 years. With a little bit of survey work and homework, you can be pretty predictive about the normal baseline hydrology of a site. It’s a relatively predictable process. But most people don’t get it right.
When you move into freshwater systems, hydrology is not predictable. Droughts, rainfall, unpredictable groundwater discharge…all of those things make it difficult to get the hydrology correct. Once you move into submerged aquatic vegetation, you are dealing with a combination of hydrology and water quality. In certain parts of the world, you are also dealing with overlapping physical impacts–from boats or commercial or recreational fishing, for example. Unless you can ameliorate those physical and biological impacts, you are going to have problems with restoration.
In a paper you published in Wetland Science and Practice in 2010, you wrote that “mangrove forest restoration should be routinely successful if a few basic ecological principles are applied at the early planning stages,” yet you also write that evidence of successful mangrove restoration on any large scale is “nearly nonexistent.” What are those ecological principles and why do people fail to apply them?
With most of the projects I am familiar with–and these include hundreds of projects overseas as well as here in the U.S.—it was initially assumed that all you needed to do was plant mangroves. Over many decades, we have seen tens of millions of dollars being put into nurseries to grow mangroves. The mangroves are then planted in places where they never occurred, a picture is taken with a child planting a mangrove and put on the cover of a success report, and that’s it. That’s the last monitoring that takes place. Now, we commonly see very specific, documented failures. My paper documents an attempt to restore over 100,000 acres of mangroves in the Philippines which largely failed.
Often times, people don’t do their homework. A lot of mangrove restoration programs are run by foresters. Foresters are tree people; they plant trees. When you ask a forester who has never dealt with mangroves before about restoration, they say, “It’s very simple. We just grow them in the nursery, find some place that doesn’t have mangroves, and plant them there. That’s what we do with other species, so it’ll certainly work with mangroves.” As long as this happens, we are going to see many more horror stories over the decades. Unbelievably large amounts of money are spent on projects that don’t have a chance.
In 1997, we developed a simple, six-step process for ecological mangrove restoration [illustrated resource]. That methodology has been adopted in a number of places I have taught, including Thailand and Indonesia. The first step is to know the ecology of the species of plants you want to restore. Any restoration project of any type for any community, including corals, should go back to this question: How does this particular ecological community naturally restore damage? All ecological communities on the planet have been impacted by something…hurricane, tsunami, volcano, flood. Without man’s intervention, they have restored themselves. You need to look at the natural, restorative, successional process as a guideline.
If you’ve had a course in ecology, you know that there is primary succession and secondary succession. Primary succession is when the plants or corals come into a totally barren submerged area or volcanic island, for example. Secondary succession is what we more commonly see with coastal vegetation. Primary succession may have been buried by dredge material or eliminated in some way. But there are probably plant propagules around, and with mangroves, those are heavy, floating seeds. Depending upon the location, there are typically grasses or other herbaceous, low-growing species that colonize these sites early. There hasn’t been a lot of research into how the early colonizers modify the soil, but apparently they improve the conditions—perhaps by oxygenating anaerobic soil–for mangroves. That’s all without human beings doing much of anything. But if you want to speed up the process, perhaps you should use the early colonizing, or “nurse” species, such as smooth cordgrass (Spartina alterniflora) [in your mangrove restoration projects.].
In the Gulf and, to some extent, Atlantic coasts, where mangroves occur, we often see Spartinavolunteer, and then a few years later, mangrove propagules volunteer inside clumps of Spartina. It’s preferential. Five feet away, if there’s no Spartina, there are no mangroves. Several other scientists have documented this natural process. Spartina, which is also particularly good for controlling erosion, might be used initially to stabilize an eroding shoreline. Then, working ecologically, the cordgrass and mangroves can stabilize pretty heavily eroding shorelines with a little help from humans.
The concept of “living shorelines” is an idea that came out of people watching natural plant communities colonize shorelines and saying, “Maybe we can use this instead of a seawall.” It’s a great concept, but it has been abused, as we don’t have formal training processes. Practitioners must be able to differentiate between an ecologically-based living shoreline and an excuse to put rock on a shoreline.
Overseas, in Southeast Asia, they have native grass species that colonize, and until recently, they’d mow them down and plant mangroves because they didn’t understand that part of the natural process. They were actually spending money fighting secondary succession. But very gradually, we are seeing practitioners–even overseas–adopting this concept.
There have been numerous reports on the shortcomings of wetland restoration. A fairly recent example is a 2012 study by David Moreno-Mateos, a University of California postdoctoral fellow who found that, on average, restored wetlands are 25 percent less productive than natural wetlands. Last year, in an attempt to pinpoint the underlying causes of those shortcomings and identify actions to address them, the Association of State Wetland Managers created a Wetland Restoration Working Group. The group developed a series of free webinars on “Improving Wetland Restoration Success,” featuring experts from around the U.S. You and Joy Zedler, both members of the working group, are among the authors of a white paper based on these webinars entitled “Wetland Restoration” Contemporary Issues & Lessons Learned.” The paper is chock full of useful information for people involved in restoring coastal wetlands. Where can our readers find this paper when it’s ready?
The white paper should be finalized this fall, but a draft is available on line now.
Many of our readers are involved in the planning and design phase of wetland restoration in coastal environments. The paper includes several recommendations related to these phases, but if you only had 30 seconds to share advice with a designer, what would you say?
Find a professional wetland scientist who does the kind of work you’re trying to do. We have 1500 or so certified wetland scientists in the U.S. Many are restoration experts. If you were going to build a bridge, you’d find a bridge engineer. If you’re going to try to restore a wetland, you need a wetland restoration professional with a track record and credentials.
As you point out in the white paper, in the case of compensatory wetland restoration, we are actually contributing to the degradation of coastal wetlands.
If you assume that the basic thing we want out of any mitigation project is at least one-to-one replacement (impact an acre, restore an acre), there is good evidence that we are not even getting close to that. A few of the papers that have been written on this—including the 2001 National Academy of Sciences book–suggest that we get even less than half. I wouldn’t be surprised if it has gotten worse. People like me, who have decades of experience, are not getting any younger, and professionals in the regulatory environment who have experience are retiring. Yet there is no formal program for passing the torch.
The changing climate is included in the white paper as one of the key barriers to meeting wetland restoration performance criteria. Obviously, climate change is a huge factor in coastal habitat restoration. What recommendations does the working group have on this?
The bottom line is that we must apply what we’ve learned about the natural system and its processes and apply it to any coastal restoration or coastal management project.
Coastal management is where we must place emphasis with climate change and sea level rise impacts. If you wait too long, a coastal wetland of any type can become so degraded it will not be able to respond naturally to sea level rise. Only healthy mangroves, marshes, and seagrasses can keep up with sea level rise—to a point. There is scientific evidence that [these coastal habitats], when healthy, can keep up with sea level rises that are ten times what we have in most places. (see papers # 501, 502 and 503 at “downloads” at www.mangroverestoration.com)
The catch here is…how do we respond? Can we respond to coastal plant communities as they become stressed? Can we intervene sooner and at least give them the opportunity to naturally keep up with sea level rise? That may sound simplistic, but it is not currently the emphasis. In the U.S., money is being distributed to address sea level rise, or “resiliency,” and a lot of it is going to projects to address severely impacted wetland plant communities. If done properly, that may have a role, but attempting restoration where plant communities have been destroyed is a tough engineering and ecological restoration issue.
My research shows that stressed mangroves can be detected. We should think about reversing the trend before the community is lost. Mangroves and marshes create their own substrate. They either trap inorganic sediments or they create organic sediments from root growth. They create peat. In many places, such as Louisiana, there are large areas of predominantly organic peat soils that have been shown to collapse once the plants became stressed. In some cases, you’re looking at decades or hundreds of years of peat accumulation. There are even forested mangroves that are 8,000 years old. If you allow that plant community to die, and allow those organic soils to oxidize, now what do you do about restoration? You can’t reverse centuries or millennia of soil accumulation over night. If you have loss of soils combined with sea level rise, that is not a logical approach.
So based on your four decades of experience restoring coastal habitats, you’d say it’s critical when selecting the restoration site to know that tipping point at which you will not have a return on investment (and I don’t just mean financial)?
It’s simply bang for your buck. If you’re going to invest funds in protecting coastlines, where is the best investment? I suggest that we are not looking at that. Many people don’t look at the real cost of coastal restoration. Recent numbers from the Corps of Engineers in New York and New Jersey show that they are spending a half a million dollars an acre for marsh restoration. We can’t afford that.
Google “cost of mangrove restoration” and see what you get. You’ll get a couple of my papers, but not much more. Turns out, it can be quite expensive, but it’s less expensive if you do your homework and try to intervene where there are stress-related issues [as opposed to restoration of a lost plant community]. Once you get into heavy engineering, the costs increase.
Do we know enough to be able to practice this type of early detection? You mentioned your paper, but has there been enough research into stress of coastal ecosystems?
No. Agencies are spending millions of dollars on “coastal resiliency” but they are not looking for projects of this nature. There is not enough money, and not enough research. We are, however, developing a process now with mangroves. We have some sites, and it’s all unfunded, ad hoc research, but we should have enough information to do this with stressed mangroves within a year or two. It makes sense: anticipate and measure stress, intervene early, and reverse the stress.
Of course, in parallel, if governments want to do restoration projects, I’m not suggesting they don’t. But it should work, and there should be documentation that it works. Built into every project there should be some kind of quantitative measures and reporting. When it gets to reporting about what worked and what didn’t work, it all falls apart because in most cases, there is not enough funding to go all the way to a publication. We are not learning from our mistakes. We use the term adaptive management all the time. But what does it really mean in the real world of wetland restoration? In a thumbnail, it’s “learn from your mistakes, publicizing that, and adapt your processes so you don’t make the same mistake twice.” I’d say that is not happening in coastal wetland restoration.
You have consulted, researched, or worked on coastal habitat restoration projects in other parts of the world. Is anyone doing a better job than the U.S. with regard to adaptive management in coastal habitat restoration?
Great Britain is doing some heavy duty planning related to planned retreat. They are actually looking at their coastline, breaching dykes that may be a thousand years old, and allowing tides to return. In the U.S., planned retreat is an anathema.
In working in nations like Vietnam, Cuba, Thailand, and Nigeria, which differ ecologically, culturally, politically, did you find any common threads in terms of factors that improve the effectiveness of coastal habitat restoration?
Expertise and training. Bringing the expertise of a professional, but then setting up training (ideally train-the-trainer programs) for the local community. You have to think about the next generation of restorers.
Among the skills and knowledge you aim to transfer in those situations, which are most important to long-term continuity of restoration initiatives?
Understanding autecology: the ecology of a single species. You must understand the biology and ecology of your target plant species, and you have to get down to the botanical level. I have done work in the Philippines where I asked, “What plant community are we going to restore here?” and they said, “We don’t know. We just want to restore mangroves.” Well, there are 26 species in the Philippines, and each has an association with another 10-20 species of marsh plants. What are their hydrological requirements? Where do they exist along the coastline?
You must also know the local coastal ecology before you start thinking about restoration. That includes uplands, margins between uplands and mangroves, beaches, etc. The role of the restoration ecologist, which is huge, is too often left out.
Have you ever found that in coming into a country as the coastal wetland restoration expert, you learned something from locals with traditional ecosystem knowledge?
That happens every place I go. 22 countries; 22 major lessons in mangrove and marsh ecology. I’ll give you an example. One of the species of mangroves that occurs in the Philippines and surrounding area, Rhizophora mucronata, has a seed that can be up to one meter in length. If you really want to, you can collect these enormous seeds and plant them in some very bizarre places, and they will grow. People have planted them and have been able to get mangroves to establish in some areas I would’ve suggested they couldn’t. However, they planted them in seagrass beds because in that part of the world, they’ve never appreciated seagrasses. So I have learned that you can convert a perfectly healthy seagrass bed into a Rhizophoa mucronata mangrove forest. But is that a good thing?
I’d like to revisit your responses to two questions you were asked in a 1998, NOAA publication on Restoring Coastal Habitats. The first question was: How effective is habitat restoration in addressing human impacts on the coastal environment? In your 1998 response, you said that “Coastal habitat restoration, properly designed and constructed, is very effective in reestablishing certain habitat types like tidal marshes and mangrove forests” but that “many coastal habitat restoration projects of all types either are only marginally successful, or completely fail to accomplish project goals. Often these failures are due to inexperienced individuals attempting to design and build projects without adequate training.” Has your answer changed since then?
My answer is pretty much the same. It can be effective if done properly, and it has been done. There are some very large, successful projects in the U.S. But those projects are not being replicated, and we’re not learning much. By and large, we do not get the most bang for the bucks we invest in coastal habitat restoration.
The second question was: What developments are most necessary before coastal habitat restoration can adequately address the range of human impacts on the coast? In your 1998 response, you said, “Routine mistakes in coastal habitat restoration design and construction are repeated because knowledge gathered by experienced professional restoration ecologists is often overridden by engineering considerations.” How would you respond to that question today?
In my response, I also said that modern coastal restoration technology “is not formally taught at any university or college, but is transmitted to a new generation of restoration ecologists largely by those brave scientists willing to admit that they do not have all the answers, and who often made mistakes before they learned by doing.” This small cadre of experienced restorationists is attempting to institutionalize the teaching of restoration.” We are making some progress there, but we are not reaching the vast majority of the people we need to reach. There are very few coastal habitat restoration training programs.
Here’s an example. Once a year, I teach a short course on coastal wetland restoration for the U.S. Army Corps of Engineers. If you are in the permitting branch of the Corps, you have to review permit applications. Some of the participants have 20 years of experience. When I ask them, “What kind of training have you had prior to coming into this classroom about what works and doesn’t work in coastal wetland restoration?” They all say “none.” They are trained in the legalities, which is important, but they have not been trained to determine if the people submitting the applications are professionals or if they are likely to have success. So there is no down side to doing a bad wetland restoration project. Projects rarely get revisited or clearly examined. I’m not talking about being overly punitive, but if a project is incorrectly designed or going in the wrong direction, that needs to be observed and reported, and mid-course corrections need to be made.
In these days of budget cutbacks and the politics that are holding sway around the U.S., there are some who would say, “We’re happy to do the mitigation, but start coming around and bothering us about whether it worked or not and we’re going to push back.” This happened in North Carolina, and there’s an article about it in the latest issue of the National Wetlands Newsletter. North Carolina realized they weren’t getting the best bang for their buck. So they got a grant, and they did some pretty heavy duty compliance monitoring and enforcement. All of a sudden, their failure rate started to decline. But the money ran out and the step-up in compliance stopped. They walked away. I suggest that’s because they got push back.
Don’t get me wrong. There are some professionals out there who work really hard and always try to do the right thing. But if a landscaper who mows the lawns in your development says, “Sure, I’ll put those plants in the ground” and there’s no compliance monitoring or enforcement, and someone takes a picture after the plants go in, bingo. You’re home free. You got your permit. Why would anyone want to put up with a gruff, 71-year-old wetland biologist like me who charges relatively high rates to do the right thing?
Who do you think has the ability to raise the profile and educational standards of coastal habitat restoration?
I’d say NOAA, as a start, because there are so many government agencies involved in management and permitting, [NOAA’s Office for Coastal Management] has a training center in Charleston, SC. But that’s a good question, and I’m curious to know what others think about that.
What is the most positive change you have seen in the field of coastal habitat restoration in the last 40 years?There is a lot more interest in it, particularly among students. One of my former students is in Brazil right now, and he says he wants to be the “Robin Lewis” of Brazil. Another colleague I trained is living in Indonesia and pursuing his PhD, and he wants to be the “Robin Lewis” of Indonesia. There are really good, young professionals coming up, and that gives me hope. They are smarter than I am. The interest is there, and if we can do a better job of reaching out, we can really turn this thing around.