SOME OBSERVATIONS ON MATUSADONA SHORELINE ISSUES

I understand that concerns have been expressed with regard to perceived declines of  some plains game species within the Matusadona National Park; and the possible need for  a hippo cull has been mooted by African Parks. This raises some complex issues, which I will try to deal with as briefly as possible;  but before doing so it is worth  noting the population estimates shown in  2014 Sebungwe surveys. These reported  59 zebra across the entire Park, all concentrated in the Matusadona hills (i.e. the escarpment southwards). None were recorded  on the lowland/lakeshore components). As for eland: none at all were recorded within the Park.

However, the survey report also notes major declines in a range of species between 2001 (the previous comparable survey) and 2014. These include elephant (±70% decline); zebra (80% decline); waterbuck (58% decline); sable (80% decline); kudu (93% decline); and impala (62% decline).  The report also notes that in most cases the declines started before 2001.

The following notes are primarily based on personal observation, but as a ”start point” it’s worth noting the following chart of lake levels during the history of the Kariba dam:

 

This shows that, with relatively minor variations, the lake remained at fairly high levels from 1964 until 1982. My own experiences began in ca. 1979, when – subjectively – there were few, if any, major concentrations of, or foci for, any lakeshore species. One had to look hard for wildlife on “game drives”, whether by boat or vehicle.

The dramatic decline of lake levels in 1982 brought about the equally dramatic changes in foreshore sightings and species populations  experienced between then and the 1990’s. As I have written elsewhere (see https://matusamana.blogspot.com/) these low lake levels saw an explosion of grazers in particular. Dr Russell Taylor is the key authority on this but, as I recall, he cited a buffalo growth rate of 10% per annum for several years. Predators followed suit, and by the early 1990’s Matusadona held Africa’s second highest density of lions on its lowland portion.

This was followed by an equally dramatic population crash when the sequence of drought years ended in the ‘90’s; and – again subjectively – lakeshore sightings reverted to the scenario I had noted when I first visited the Park in the late 1970’s.

The salient point that has to be understood is that the Matusadona lakeshore – the Park’s prime tourism area – is a human artefact created by the lake and hence by the dam itself. The dam and its management are crucial factors in the well-being or otherwise of valuable once-natural ecosystem components both upstream and downstream - e.g. the Mana Pools alluvial terraces and the Matusadona foreshore & lowlands.

As a first point, then, it is equally important to note that, as things stand, the Kariba dam is currently managed solely for power generation, without consideration for any environmental issues that may arise. It’s worth noting that, broadly speaking, large releases through the dam can, if well-timed,  be beneficial both upstream (by exposing Matusadona  lakeshore areas) and downstream (by rejuvenating the Mana alluvial terraces).

It may therefore be useful for the Zambezi Society to consider approaching the Zambezi River Authority (ZRA) with a view to incorporating an environmental component into dam management . However, that is not the whole story. In the case of the Matusadona, confounding factors arise in the form of natural progression. The lakeshore populations depend primarily on the development of palatable grasses as lake levels fall. This area was initially colonised primarily by Panicum repens (torpedo grass), which most grazers consider extremely palatable. More recently, though, Panicum has – by observation – increasingly been replaced by considerable areas of various other forbs and grasses, many apparently unpalatable; thus – by inference – accompanied by growing grazing pressure on such Panicum as still develops.

As regards hippo: the 2014 survey quotes a Matusadona population of 404 animals,  which – by definition – occur almost entirely on the Park shoreline (although they can range a surprising distance inland as well, if pressed for fodder).  A hippo can eat up to 70kg of grass per day, which comes to a ballpark total of 28 tonnes per day. This – on the face of it – makes them a prime candidate for a “population reduction exercise” – i.e. a cull.

However, a fair number of elephant – around 500, according to the 2014 survey,    also focused largely on the lakeshore  - can also eat around 100kg a day. That includes browse, of course, and I don’t know how many have been lost to poaching since the survey, but in May this year we were regularly seeing groups of up to ten animals on the foreshore in the Palm Bay and Elephant Point areas. They can’t be ignored, either. All in all, the situation calls for some careful management planning.

Dick Pitman

THE ZAMBEZI SOCIETY

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LET'S TALK ABOUT THE WEATHER

Sally and I always plan to make an annual pilgrimage to Mana during the rains. This time, we spent an amazing - and well-timed - few days down there in mid-December. As always, the transformation was stunning. And it always reminds us, very forcibly, that those spectacular dry-season concentrations of wildlife on the Mana terraces are the result of one thing, and one thing only: rain. Without it there is, quite simply, no Mana. Just desert.  

It rained a lot of the time. New grass was well established across much of the alluvium by the time we got there, and grew almost audibly during our seven-day stay. Meanwhile, the Faidherbia albidas were still in leaf; but a lot had fallen and died since our last visit – something I’ve written about before, but can be summed up by the proposition that the F. albida woodlands are largely a single-age stand and have reached the end of their lifespan. 

Meanwhile, the alluvial terraces are undergoing a slow dessication and there’s no regeneration except on midstream islands, which seem likely to be the “new” Mana woodlands at some indeterminate future time, if the Zambezi continues its slow shift northwards.

The interplay of sun and cloud on a haze-free Zambian escarpment is just one of the great
pleasures of a rainy-season visit to Mana

The river itself rose a couple of feet and turned to dark chocolate, running hard and scattered with dry-season debris of broken branches and drifts of dead leaves. Long Pool filled more or less before our eyes, as did Chiseseku Pool; and on our way out the Rukomechi River was in full flood. In other words: everything was as it should be. Mana was resting and recovering after a long, hard dry season. 

But – here’s where it all gets a bit speculative - I don’t think this was ITCZ rain. Neither did it look like “ordinary” early wet-season weather, with cu-nims building up in clear blue skies before erupting in howling storms (although there may have been some of this before we got there, as witness the destruction of part of the Mana clinic by a falling mahogany ). Mostly, the skies were dull grey, and the arrival of rain marked mostly by a gradual darkening in the overall cloud cover. Some funny things are happening to our weather, and the scene shown here (right) was something of an exception.

These clouds - when they happened, which wasn't often - were obviously kicked off orographically by the Zambian hills in the predominantly south-easterly wind, and usually that’s where they stayed. The Royal Zambezi airstrip got a drenching, and probably gave an exciting time to some aerial transfers from Lusaka. 

Mostly, though, on our side of the river we got a lot of featureless grey cloud coming from the southeast, one or two heavy falls, and a disconcerting amount of drizzle with rare outbreaks of sunshine, usually in the late afternoons (and creating some absolutely stunning scenes when it happened). 

So what were we looking at? Are we, in fact, witnessing the first effects of impending climate change? And if so, what are the implications in terms of managing Mana Pools, and indeed all our other wild areas? Is this an Elephant in the Room, that we have to confront?

Many readers will be familiar with the concept of the Hadley Cells, associated with the ITCZ, which hitherto has been our main source of rainfall across most of Zimbabwe. For those who aren’t – a brief (and very oversimplified) explanation. The ITCZ itself is the result of convergence and convection focused on the solar equator, which itself moves north and south between the Tropics of Cancer and Capricorn. The ITCZ follows the sun northward during our winter, giving us our dry season, and southward during the summer, and traditionally brings us our rains.

Convection – as, again, most readers will be aware – implies the upward movement of warm air, which is exactly what happens in the ITCZ. Many who fly between Europe and southern Africa, often at around 40 000ft, will have noted the weaving that takes place between thunderheads with their anvils extending high above their aircraft, accompanied by spectacular lightning, particularly on night flights.

However, what goes up must come down, and this applies as much to air as it does to aircraft. All that air drawn upwards by convection within the ITCZ has to come down again, somewhere. Some of it does indeed come more or less straight down, as witness the bitterly cold air often accompanying the rainstorms below. But a lot of it doesn’t, especially at high altitudes. Instead, it is transported northwards and - for us in the southern hemisphere - southwards for considerable distances before descending to lower altitudes, from where it is – once again – effectively “sucked” back towards the ITCZ. It is, of course, a lot more complicated than that, in real life; but overall, the net effect is that circulation: up at the ITCZ, then south; then down; and then back towards the ITCZ again. This simplified diagram shows the general idea.

Now comes the joker in the pack, and it’s climate change. Deniers should probably stop reading here, because I personally am convinced that it’s real and, moreover, mostly caused  by human activities such as burning fossil fuels and converting forests into fields. 

There are reams of literature devoted to the potential impacts of climate change on the ITCZ and the associated Hadley cells, some of it apparently contradictory and most of it opaque to the lay reader, including myself. However, two indisputable facts emerge. One is that changes in the ITCZ's structure are virtually inevitable; the other being that we here in Zimbabwe - dependent on the ITCZ for most of our annual rainfall and lying under the influence of the associated Hadley cells - are going to enjoy or endure the impacts of these changes, whatever they may turn out to be. 

For example, I have a purely personal and subjective perception that we are seeing an increasing number of cloudy and often drizzly days during our Zimbabwean winter, and furthermore extending later in the year. In mid-December, our ambient air temperature at Mana hovered around the mid-20’s °C. There were none of those balmy evenings – or hot, restless nights. We were glad we’d packed pullovers. I realise this doesn't exactly smack of "warming", but it could square with a strengthening or extension of those cold low-level air inflows into a changing ITCZ.

Meanwhile, climate change has – at last, and quite suddenly – gone from fringe concern to institutionalised global obsession. So, too, has the maintenance of biological diversity and functioning ecosystems. Witness, for instance, the rise of snappy catchphrases, such as “Nature Needs Half” – that is, at least half our global land surface retained in as natural a condition as possible.

This has caused an influx of several more elephants into the room, notably the issue of sheer human numbers, which is often considered to be simply too fraught with sensitivities to be discussed.

This is at last showing some signs of changing. Nonetheless, by far the majority of the literature tends to focus instead on the vital importance of reducing greenhouse gas emissions – largely from burning “fossil fuels” - and maintaining carbon “sinks” – notably forests. Moreover, there’s big money becoming available to do just this. 

Late afternoon sun on newly-grown grass creates some of the loveliest lighting you'll
ever see in Mana Pools. 

Mana – indeed, all our major Parks – are ideally placed to capitalise on this trend, and in fact Mana is already doing so, resulting from the inclusion of Mana Pools – and, indeed, Matusadona – as “core areas” within the UNESCO Biosphere Reserve, and of Chewore, Sapi, Chawara and Hurungwe as “buffer zones”. The Global Environment Facility (GEF) has earmarked some US$50million for the Reserve, including the critically important settled areas on the Park and Safari Areas boundaries.

There has also been some excellent work coming out of Chinhoyi University in respect of potential climate change impacts within the Biosphere Reserve (notably O L Kupika et al). This is a great start, but what about long-term sustainability? I have yet to see such work translated into - for example - specific Park and wildlife management plans in the face of the climate crisis. Maybe this is because there's actually very little we can do about it. There's not exactly much scope for moving entire wildlife areas around. Or maybe I'm simply missing something; if so, I'd be delighted to hear about it. 

Which brings us to another of those elephants crowding into the room, one of which is how funds for our Parks are  currently raised. The conversion of Parks into a Statutory Authority – responsible for its own financial survival - hasn’t been helpful, in view of current events. There are currently two main ways in which our wildlife areas can generate their own funding. One is hunting – an activity that is increasingly deplored by much of the world, and – justifiably or not – seems almost certain to decline in popularity and therefore revenues.

The other is tourism - preferably of the international, high-rolling kind. This is having all kinds of associated negative impacts, notably the rapidly decreasing opportunities for the true “owners” of our Parks - the Zimbabwean public - to gain access to them. This has to change, simply because we need the consent of this public if the Parks are to survive at all. 

Thinking beyond that, however, let's also look at a possibly minor but nonetheless important irony involved. International tourism relies almost entirely on cheap and abundant international travel by air; and air travel makes a small but growing contribution to atmospheric greenhouse gasses and global warming. Around 2.4% of global emissions come from aviation. Together with other gases and the water vapour trails produced by aircraft, the industry is responsible for around 5% of global warming.

At first glance, that might not seem like very big contribution. At present, only a small percentage of the world flies frequently. Even in richer countries like the UK and the US, around half of people fly in any given year, and just 12-15% are frequent fliers. The capacity for future growth seems immense. Meanwhile, Mana is financed almost entirely by – indeed, currently managed for – international tourism. In other words, we are conniving at – encouraging indeed – such growth.

Only one small problem, of course: international tourism has now collapsed due to the COVID crisis, and so has the Authority’s income. This will no doubt pass, but it’s going to take time for the industry to revive. The present drive for local domestic tourism is helping, but Parks stations are still desperately short of cash. 

I believe we require a radical reappraisal of the legislation governing our Parks, including the Parks Act and the Statutory Authority status conferred some years ago, so that we can maximise on the funding opportunities now opening up worldwide. The Parks Act itself  was basically written in a different era, to put it mildly, way back in 1978. It has – with some amendments –served us pretty well over the years; but the current global scenario does, I think, warrant an overhaul, to bring us in line with current global thinking and funding.

Here’s the current wording of the Parks Act:

"(1) The purposes for which national parks are or may be constituted under this Act shall be—

(a) to preserve and protect the natural landscape and scenery therein; and

(b) to preserve and protect wild life and plants and the natural ecological stability of wild life and plant communities therein -

Fireball lilies near Nyamepi - a visually striking display of
Mana's biological diversity

for the enjoyment, education and inspiration of the public".

It’s that last line -  explaining why we're doing all that preserving and protection  - that’s the problem. It may have been fine in 1978, but in 2021 - over 40 years on, and in view of what we know today - it does sound horribly blinkered and parochial. 

Instead, I'd suggest that the Act  should be redrafted to reflect today’s growing realisation that the survival of biodiversity and natural areas is the foundation of human health and essential to the future wellbeing of mankind. 

With around a million animal and plant species currently threatened with extinction worldwide and 70% of the Earth’s surface already modified by human activity, this foundation is clearly in serious trouble. Therefor, the Act should also reflect the imminent and severe threats that have become apparent since its drafting in 1978.

In other words: we need to up our game and present our Parks and other conservation areas as vital to human survival, rather than as mere amusements for visitors. With a significant proportion of our natural landscapes already under some form of protection, we are well placed to do so*.  I’m not about to propose alternative wordings; I’m merely hoping to sow the seeds of an idea that will – if accepted – require a major effort by a suitably composed task force, led by the Parks Authority and sanctioned at the highest levels of government, to consider and implement. 

In this respect, I’m reminded of an international conservation event that Sally and I attended some years ago, at which one bright young sprig stood up at a plenary session and boasted that “his” Park – an important terrestrial/marine complex somewhere in the Caribbean – “was entirely funded by tourism”.

When he’d finished, I stood up in my turn and said: that’s all well and good, but what happens when the tourists stop coming?”

He looked at me as if I was insane. The possibility of such an event had never even crossed his mind.

I can’t help wondering how he’s feeling today....

All the components of a healthy habitat - trees, grasses, water and wildlife - looking vibrant, even on a dull day in Mana

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*January 12 2020: The High Ambition Coalition (HAC) for Nature and People, launched this week at the One Planet summit for Biodiversity, aims to secure a global agreement to protect at least 30% of the planet’s land and at least 30% of the planet's ocean by 2030 (30 x 30 is the plan's snappy slogan).

The United Nations World Database on Protected Areas ( WDPA ) quotes Zimbabwe as having 27.2% of its land under protection, compared with 14.9% globally. This means we are in fact quite well ahead of this particular game.

The raw figure does of course beg a lot of questions, not the least being its accuracy; how well are particular species, ecosystems and habitats represented or otherwise; what condition are they in; how effectively are they being managed and protected and by whom; and how rapidly are they currently being eroded or otherwise.

30 x 30 has been signed by some 50 countries. Zimbabwe isn't one of them. But the fact that we're almost on target anyway, and got there on our own initiative, should at least encourage us to try harder, and to continue to be leaders rather than followers in this respect. 

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 SOME REFLECTIONS ON THE MATUSADONA SHORELINE &  CHANGING LAKE LEVELS 

Aerial photograph of the Nyamune/Kanjedza  shoreline area, taken in October 2020 by Peter Wienand.
All other photos by Dick Pitman.

Readers may recall that I wrote at tedious length about Mana Pools sometime before lockdown; and since both Matusadona and Mana are seminal catalysts for my personal 40-year involvement in wilderness conservation, it’s only fair I should give Matusadona a crack of the whip, now that Sally and I have actually been able to spend some time on the Park shoreline after months of frustration.

Matusadona and Mana Pools share  a hugely important common factor: the impact of the Kariba dam. But whereas Mana’s dominant feature – the alluvial terraces (or floodplains, as they are often wrongly  called) continue to flourish despite the dam, the Matusadona lowland’s  dominant feature – its shoreline – exists because of the dam. It is, in essence, a human artefact. 

Ca. 1980; elephant tearing Panicum from the submerged
foreshore and cleaning off the sand and silt.

I first set eyes on both of them some 40 years ago, and it seems odd to reflect, today, that Lake Kariba had only existed for 20 years at that time. Now we’re celebrating its 60^th anniversary. The lake  filled during the 1960’s and, by the time I first saw it, Kariba had been more or less full throughout the 1970’s, without any really significant fluctuations. There was very little “shoreline”, as such – the water extended more or less up to the bush line – and there seemed to be little reason to anticipate any major changes in that regard.

The Matusadona I recall from those days harboured, in relative terms, comparatively little by way of wildlife concentrations. You had to work for your sightings; and inland “drives” – in direct contrast to today’s scene – were often more productive; and there weren’t many roads on the shoreline anyway. 

This all changed dramatically in the early 1980’s, when lake levels plummeted due to drought.  The lake became ten metres shallower. The Matusadona has, by and large, a gently shelving shoreline, and we watched in some awe and no little apprehension as vast expanses of lake bed were exposed for the first time since Kariba filled. Islands – including Fothergill, where I spent much of my time – became peninsulas.

Waters that had lapped  at the doors of tourist chalets receded out of sight and were replaced by less-than-inspiring expanses of red or grey silts populated by dead trees. Harbours dried out altogether, and boats had to be moored wherever shelter could  be found. The only plus, it seemed, was the ability to harvest  vast quantities of fishing tackle wrapped round previously-submerged snags.

Fothergill Island after the lake went down,  ca. 1982

This was disconcerting, to say the least, and especially so to the tiny handful of tourism operators – two, to be exact – who had set up shop at a lakeside and suddenly found themselves far inland.  It was also disconcerting, I might add, to boat skippers (I was among them) who equally suddenly found themselves  hitting treestumps in what, until then, had been large and harmless expanses  of clear water. But what also became equally clear was that – far from being the kind of timeless verity one wrongly but  intuitively expects from a National Park, the Matusadona (or its lakeside portion anyway) – was really the gigantic laboratory experiment you should foresee if you suddenly plonk a 2000sq mile lake down in the midst of relatively virgin Zambezi Valley wilderness. It was a rude awakening.

The near-immediate biological response to all this was a confusing riot of new vegetation, with outbreaks of sedges, forbs, reeds and grasses, the latter including – but not limited to – the Panicum repens we have come to regard as a reliable dry-season  food supply for grazers in the Valley portion of the Matusadona. And the result was the spectacular explosion of species such as buffalo, zebra, waterbuck and impala that persisted until the 1990’s, when  a combination of droughts, floods and high lake levels caused them to go into decline again. 

"A confusing riot of vegetation" developed on the
newly-exposed shorelines after the lake went down in the
early 1980's

Bear with me. I’m – circuitously, granted – getting closer to the point that inspired me to try and write this piece. In July 2018, Lake Kariba peaked at 487m - not far off its "full supply height" of 488.50m.  (NB - these levels are relative to "sea level", which is used as a constant reference point).Today, as I write, Lake Kariba is already quite low, at around 478m, or about 3m above its 475.50 minimum supply height. The question we have to ask is whether we can ever expect it to fill again, to anything near its maximum (in other words, to get 10m deeper again).

The question is somewhat confused by what may have been spillage intended to facilitate work on the dam's stilling pool. Nevertheless  – barring truly spectacular climatic events - the answer may well be "No". This is because of the ever-increasing demand for power from the dam, in the absence of alternatives, caused by what seems to be a ever-ending installation of new and increased turbine capacity. 

For as long as I can remember, there has been debate over Mupata Gorge, Batoka Gorge, and potential new thermal power stations. But nothing has happened, and even if it began tomorrow, construction of such alternatives is going to take a long time. These low lake levels, I’d bet good money, are here to stay for the foreseeable future, barring massive changes in climate that bring equally massive and sustained rainfall to the Zambezi catchment.

Therefore, the extended foreshore we are seeing today can be regarded as a probably permanent – and substantial - extension to the Park’s land area, and a continuation of the Matusadona "living laboratory" experiment.  

Now: I – and, I think, many others – have come to rely heavily on the presence of palatable grasses on the Matusadona lakeshore to provide sustenance for grazers during the dry season and pleasant “game viewing” for ourselves. The conventional wisdom is that this grass is primarily Panicum repens that is refreshed annually by a rising lake. But is this still true?

The Nyamune river in flood, January 2006

What sparked this all off, in my own mind, was pure (and doubtless somewhat limited) observation during our recent sojourns in the Nyamune River. I'll freely admit that my knowledge of grass species is abysmal, having for many years laboured under the belief that Hyparrhenia was a form of mental disorder. However, it was the elephants – followed by the baboons – that first drew my attention.; and here I should note that,  due to low lake levels and a boat that draws the best part of a metre, we were moored in a little indent in a steeply sloping bank a long way, putting it mildly, from the bush line.

There was no fringing grass or - for that matter – no eles standing in the water, pulling Panicum up by the roots and beating the mud off it. Come to think of it, though, I haven’t seen that behaviour in a long while; but this may say more about the timing of our visits than anything else.

Anyway: the grass closest to us on the bank – whatever it was – was quite green,  dense and  extensive, and was seeding; and  we never saw elephants feeding on it. Nor anything else, come to that, except a troop of baboons that seemed to have trekked several hundred metres from the distant bushline to feed on it, having painstakingly stripped the seeds from the stems.

Instead, the elephants, when they came – which was often – were focused on a much shorter, but obviously well-cropped grass species, further up the bank, which they equally painstakingly kicked loose with a forefoot, thus ripping it out by the roots and ate without bothering to clean it off. 

At the head of the bay – which I could admittedly only examine with the aid of binos or a long camera lens – the situation seemed different, with a belt of what I assume was Panicum that was constantly grazed by impala and waterbuck. Zebra, however, seemed to favour apparently almost bare areas further up the catenary. 

A "long shot" up the Nyamune River from our mooring. This scene was seldom bereft of mammalian wildlife, except in the very early mornings. 

And we never saw elephant on that apparently lush fringing grassland. They appeared to have the same taste in grasses as the zebra; here too, they spent a lot of time grazing higher on the shoreline, just as they did close to our boat.

Same background scenery as above. Elephants appeared here every afternoon during our visits, always feeding higher on the shoreline than the impala and waterbuck 

Ok. I’m well aware that I’m only focusing here on a tiny percentage of the Matusadona’s land area, two-thirds of which lies south of the Matusadona range. One third – roughly 400sq km – lies on the Zambezi Valley flatlands, largely composed of mopane woodland with some notable outbreaks of jesse bush.

But that area is now significantly expanded by currently exposed lake shore, which as I've already noted seems likely to remain that way in view of the demands of the Kariba turbines. And those exposed shores sustain the Park’s major wildlife tourism focus. Meanwhile the periodically high lake levels that we believe are necessary to maintain the much-valued grazing resource seem likely to become merely a fond memory.

High lake in September 2010 - Nyamune River, Matusadona National Park

Therefore a  key question seems – to me, anyway - to be:  are those fluctuating lake levels indeed still important to the foreshore grasslands? To what extent, today, are those grasslands rainfed, thus becoming independent of the vagaries of the lake? 

Another factor that's been making me think about all this is the apparent differences between the extent of the lakeshore grasses during our recent trip. As can be seen from the aerial photograph introducing this post, the grasses in the Nyamune area seem to be of small extent and highly focused on bays and inlets. But - thanks to Changa Safari Camp, where we spent a welcome overnight relief from cooking our own meals and  showering in still-frigid lake water - we took a "game drive" by vehicle to the Kemurara area, aka Sanyati West - one of the most gently-shelving shores in the Matusadona, and historically famous for its buffalo herds (now recovering, it's good to hear). 

Buffalo in Sanyati West, during the low lake levels of the 1980's and resulting population explosion.

For today's scene in the Sanyati West area, see the photo at the foot of this post. Simply put, the whole place was apparently grass-covered, and there were elephant all over it. Is this all Panicum? If not, what other species are involved? How palatable are they, to the Matusadona's range of grazers? And to what extent does this cover now depend on rainfall, as opposed to periodic lake level fluctuations? The same question, incidentally, has occurred to me during occasional visits to Rhino Safari Camp, near Elephant Point on the north-western Matusadona shore, which seems to enjoy similar year-round grass cover. 

We can in fact also now add the proposed Batoka Gorge dam and its possible impacts into this mix, since – of all the alternatives – this does seem to be the one that’s progressing beyond the pipedream stage.

It may be that these factors have already been researched and conclusions drawn from them. I also recognise the complexities involved, that I haven't even touched on, such as nutrient availability and replenishment, soil and substrate characteristics - which are far outside my limited competence to discuss in any meaningful manner - and the ubiquitous presence of the "soak zone" that provides constant (and constantly shifting) sustenance to the entire lake shore. In short, I’m asking questions, not providing answers, and doing so as no more than an interested layman.

Nevertheless, it seems self-evident that changing Matusadona lakeshore conditions can be of critical importance to the wildlife it supports, the wellbeing of the Park, and the income it contributes to the Park's conservation via tourism. We’ve already had one scare associated with shoreline vegetation – the so-called “floppy trunk syndrome” that afflicted a significant number of elephant a couple of decades ago, and that was widely attributed to an as-yet-unidentified exotic invader. 

Subjectively, there was a perception that the problem's disappearance was linked to rising lake levels. Objectively, I've never seen any scientific examination of this perception. But the episode should remind us - once again - that we are dealing with an enormous, uncontrolled, and - in the Zambezi Valley biological context - unprecedented "laboratory experiment". We may hope that the wildlife population increases associated with past periods of low lake levels will be repeated. But ecology - or Nature, if you like - is full of surprises, and not all of them are nice, especially where human artefacts such as the Matusadona lakeshore are involved. 

The new custodians of Matusadona have a lot on their plate, not the least being the control of ivory and other poaching across the Park’s ±1400sq km. Nevertheless, I'd suggest that a research focus on the current biological status and potential futures of the Park lakeshore is a clear and  present need?

The Sanyati West/Kemurara shoreline after sunset, during our recent November visit.